Actually, the PeAq spells explicitly mention Corpus or Animal requisites to effect the appropriate creatures, while Aquam's second sentence mentions Corpus involvement being necessary, so there's no dysfunction. But you're generally right about the inconsistency of the guidelines.
Only Creo can effect creatures. :mrgreen:
... Oh my what? 
That's hilarious.
Typo humor ftw. Even better than damnyouautocorrect. 
Exactly! 
Given that page 77 says all artificial items created need a finesse roll and what Houses of Hermes:Societates says about the difficulty of said finesse roll and what Hermetic Projects outlines for a spell with similar parameters that does create another artificial thing I do not conclude that the roll for CtMT had the finesse roll eliminated. The EF may not have been explicit for CtMT, but the finesse roll is still necessary.
Keep in mind, if we take your position CotSG shouldn't require a finesse roll, because it is nearly identical to CtMT. Taking my position, the EF for the Creo spells doesn't include modifiers for time. Which is more consistent with page 77 of the core book and page 60 of HoH:S?
considers Neither. Probably the most accurate version is as follows:
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The rules for CtMT are a holdover from previous editions, so the Finesse roll was probably forgotten in the update. In play, a troupe should either add the correct Finesse roll, or rule that this spell is an exception to the normal rule due to a beneficial experimental result long ago, and has spread across the Order because it is special.
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Creo includes modifiers for time, just like Rego.
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Increasing the duration of either kind of spell does not help the Finesse roll, due to the usual rules. However, it is possible to break a complex task into smaller components, so that multiple castings of one or more crafting spells have much easier Finesse rolls.
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A magus does not need or benefit from a mundane Ability that corresponds to any given crafting magic spells. However, it is probably reasonable in some cases to rule that a magus using many spells to achieve a result (as in a magus who hews giant stone blocks and uses non-crafting magic to move them into place needs an Ability that represents moving the blocks into the right places, although a crafting spell that adds a block to a stone structure should not require a mundane ability.)
Anyway,
Ken
Anyway,
Ken
The text of the spell is a holdover from previous editions, I'll grant you. The rules for artificial objects needing a finesse roll are mentioned on page 77 of the 5th Edition text. You say that all other Creo spells include a finesse magnitude, and because the other spells do and CtMT doesn't means that CtMT doesn't? Is that your position? By and large spells that need special rules for adjudicating their results have them included in the text of the spell. It is possible that it is an oversight and you might be correct that CtMT doesn't need a finesse roll (and this be eligible for asking David Chart about errata on the issue), but nothing in the text of the spell or the RAW elsewhere indicates that a finesse roll is unnecessary or eliminated. Were it the case that CtMT doesn't need a finesse roll then the spell for the ship that I mentioned, which has the same +3 for elaborate design/intricacy wouldn't need a finesse roll, either. CtMT and CotSC are nearly the same, and with regards to intricacy or elaborate design, they both add +3 magnitudes to account for the difficulty.
Saying that CtMT doesn't need a finesse roll simply because the finesse requirements isn't explicitly stated is a premise that isn't supported by the rules, and it's not even supported by the other Creo spells that do need finesse rolls. I seriously doubt that it is an exception because it's useful to the Order. Then, what is the correct finesse roll?
It does? Then why does it not for CotSC? CoTSC requires nothing more than Int+Finesse EF of 9, not 18+ (presuming it takes a year to build a ship from ground up). Is the reason the EF is 9 rather than 18 because of the +3 for intricacy? If we use modifiers for intricacy as a reduction in EF here, for one spell, then it would certainly hold that the same should apply to CtMT. Let's be consistent, shall we? If Creo includes modifiers for time, and we apply increase magnitudes for intricacy or elaborate design to the spell, then they must both roll for finesse. I'll point out that were it the case that Creo needs to include the finesse modifiers for time, then no one, absolutely no one would ever do a Creo spell to make something, because of wasting the vis is much more likely since you're basically checking twice for a botch, once for the spell and once for the finesse roll.
From a story point of view, I'd rather player spend vis for stuff and make the EF for it low (as I think the RAW supports, as evidenced by the Creo spells that list their EF as being significantly lower than one would expect if it did include time modifiers) and even simple to make it virtually assured. Vis has more "value" than raw materials/silver used to acquire raw materials, and if characters are willing to part with things of greater value, I'll let them and throw them a bone. Call it a HR, if you'd like. 
And they were written before the other craft magic rules. ArM5 came out more than a year before Covenants, which came out before HoH:S and A&A. Just another reason for agreeing with you.
I really had thought this spell has been mentioned in the craft magic rules somewhere, but I cannot find it so I guess I was wrong.
Need, no. But HoH:S disagrees with you on benefiting. A mundane Ability that corresponds to the item being crafted can grant a bonus for familiarity, up to +3 IIRC.
Also, there is no stipulation on the limits of craft magic. Vis tends to limit Creo craft magic. But Rego craft magic can get very broken. With a substantial amount of material (which may also be able to be reworked with use of another Rego spell), a magus can make many attempts. Sure only one a hundred will reach d10x2x2. But there are nearly a hundred days in a season, so that's only one attempt per day. That wouldn't even interfere with studying. A magus could easily try this eleven times a day to get to a substantial chance of rolling 40+ at some point in a season. With not unreasonable values in Finesse and other places, that could easily be an Excellent+10 item. (I once got this kind of result myself for an item to be my Talisman, though that was roughly Excellent+20. I vetoed my own result.) So, let's say you just made your sword Talisman this way. It now gives you +10 attack, +10 defense, and +10 to lab totals to enchant it. Due to the frequency with which this can happen, it becomes quite a useful thing to do and things get quite broken. Also, assuming you've got some useful materials in an item, this thing is better than anything with Verditius Runes will be. This is why I like to cap craft magic using the mundane Ability cap for Excellent items. Now the statements about Verditius magi not using craft magic make sense, and things tend not to break nearly so easily around craft magic. It didn't even require a house rule, just the interpretation that the limit from the mundane Ability still applies, and I've seen no rule saying it doesn't.
The rules do say Creo craft magic uses the same difficulties as Rego craft magic.
The rules also say that using Creo does not require a roll if the ease factor is 9 or lower. So if CtMT has an ease factor of 9, no roll is needed.
So, now what happened to that +9 you ask about? That's where I thought I'd read something about +3/magnitude devoted to intricacy or something like that. But I seem to have misremembered that. Too bad, if I hadn't then we'd see CtMT's ease factor drop to 9 and not require a roll, which would be consistent.
Where? Because, then the roll for CotSC is unnecessary, too.
The top right of the top-right box on page 61 of HoH:S. I believe this was included to make sure Creo was generally still useful while not totally supplanting the value of mundane craftsmanship.
I see.
Minor niggle it says you don't need to roll if you don't want a result better than 9. And 9 is a poor result. Finally where does that leave CotSC, since it lists needing a Int + Finesse of 9?
This whole area is a mess, I think I'm going to go back and stick my head in the sand and ignore it.
As I keep saying, this may be misleading. Sure, if you are utterly unfamiliar with boats, you'll get a -3 penalty, and it's true that if you have Craft:Shipwright 6, you must be familiar with boats - avoiding the penalty. But it's a little like saying that an academic degree makes you enjoy comics more, in that you'll enjoy a comic more if you can read, and if you have an academic degree you can (presumably!) read.
This is, I think, a crucial issue - and one rarely discussed.
The rules for item quality in C&G all assume craft totals - there's no die rolling involved. Personally, it seems quite reasonable: unless you are "experimenting" and pushing your limits (and that's what workshop exertion is for), basically your results over a season are reproducible and not quite subject to chance. Sure, the occasional day of work may yield problems, but over the course of the season it all balances out It's the same idea behind magi lab totals having no random element, barring exceptional circumstances. Similarly, the rules for artistic creation in A&A have an "aesthetic quality" that is basically a lab total: a fixed quantity, to which you can add a small extra if you take risks and experiment.
On the other hand, rules for craft magic in Covenants and "artistic" magic in HoH:S assume you are rolling against a given Ease Factor. It's by no means obvious to me how to translate an Ease factor into a Craft Total or Aesthetic Quality, or viceversa. The most natural way to do it seems to have Ease factor = Craft Total +6 (or Finesse Ease Factor = Craft Total +9), but it's really a very different mechanic: rolling gives you a much wider "spread" than adding up a craft total or aesthetic quality.
It's a problem born of rules creep; Covenants was fairly early but C&G and A&A have better systems for crafting, and HoH:S muddied the waters. Given my druthers, I'd give magi a Craft Total of Perception + Finesse - 3 to determine the quality of their work (no dice rolls), and force extra magnitudes on the spell for work more than a single craftsman a day (+Magnitudes for 'size' of workforce). If/when players are relying on repetition and a high die roll, you know something's gone off the rails. Maybe no penalty for Creo magic to make rituals seem like less of raw deal.
Conceivably a magus could gain enough Per+Finesse to exceed the best craftsmen at anything, but that level of 'problem' is on par with Flambeau doing a better job of killing things with than a knight because of Pilum of Fire.
One thing I've thought of, in answer to the whole repeat until you get to a high die roll[1] is to make Rego Crafting on this scale more like a seasonal activity. I mean, if we're talking about making spells with D:Concentration why not really scale up the time frame and work out some bonuses?
I'm not there yet, but something along the lines of +1 per week focused on pursuing that high roll, and you get one roll per week to account for the lucky roll. One could make 13 things with a +1 bonus to their Finesse roll or 1 thing with a +13 to their finesse roll. As a player and an SG, I like the idea of spending a season to do something like assemble a tower from the component pieces and have a reasonable chance of doing so. I'd still leave the modifiers for time involved in computing the EF. IF you're only interested in creating the one thing you'd roll each week to see if you finish early and maybe can salvage the rest of the season at no real penalty.
[1] The other thing here, is that some things will need a lot of raw materials, glass and iron are reusable, paint, wood and marble blocks are not.
Oops on familiarity providing +3.
+3/magnitude for intricacy is something I posting quite some time ago, but I might not be unique with this rule.
I too had noticed the difference between craft totals for mundanes vs dice rolls for magi.
If I had my druthers, the entire issue of "how many craftsmen" would not be part of the target calculation, since spells already account for the type and quantity of material. Similarly, the amount of time a mundane craftsman needs is also irrelevant. What matters is the amount of skill needed. So crafting total for a rego spell might be 6+3/extra magnitude, maybe + Finesse too, and that's it, though I'd recommend to allow a magus with FFM to be able to adjust for intricacy as well as T/D/R.
If all Finesse "rolls" were converted in a similar way, accounting for the loss of a die (+5), magical aimed attacks would involve 1 die roll (for casting), and the rule for "I want to do something interesting with spell X" would be clear.
Then we'd add a MuVi guideline for increasing intricacy, similar to T/D/R.
And maybe some Hermetic Virtues, such as "for every 10 points your casting total exceeds the spell level, the associated Finesse Total gains one level (+3) of intricacy."
Anyway,
Ken