Note all the "ifs" and "probablys" and "expect" and "in your saga."
I also didn't realize that the only options are those found in the box!
Utterly ignoring AM4, I did notice the bit in TC&tC about magi coming along with the crusades and blowing away sahirs, who could do nothing in the face of Parma. So I'm comfortable associating magi and crusaders.
Which seems kind of odd. Parma can cause a Sahir problems, but a Jinn with a mundane sword can run a magus through quite well. The rules have Jinn as a form of compensated servant (especially for Faerie Jinn who are gaining vitality and vis through the role) not a bound servant that is going to be banished when the Sahir dies. If you kill a Sahir, that doesn't mean that his spirits aren't still going to hunt you down and try to kill you. If the decide to bring friends it might be a way to described the Plague by X flaw...
Sahirs make really good ninja death squads. I'm just saying.
Anyway, like I said, the best reason to create a cult is a theurgic cult - but that brings to mind the question of "what are you trying to do as a theurge?" More powerful spells than usual at the price of jumping through some hoops? Are you trying to get a couple of F/T combinations that you can effectively use non-ceremonial (and powerful!) spontaneous magic in? Do you want a cheap Flexible Formulaic Magic at the expense of Slow Casting with the option to turn both off? Names of Power that can be used in the lab? Did your troupe let you Focus in theurgy? (cheat ) Or do you know some daimons that can help you in exchange for vis?
If you want to do some of those, then having a cult of fellow theurges aids in the first invocation of a spirit.
If their spells-with-penetration fail, non-hermetic wizards will move to spells that don't rely on penetration rather quickly. After all, everybody has to deal with creatures with Might, which have Magic Resistance. Parma gives hermetic magi a free hand for a round or two, unless the opposition is entirely unable to deal with MR.
I'm not so sure about the conclusion you've drawn regarding non-Hermetic wizards. First, in terms of MR amounts, my understanding is that in all but the most Mythic of Mythic Europes, creatures with MR matching that of even most younger magi are quite rare to encounter by chance (though this doesn't apply quite as much to Sahir since they do actively seek potentially powerful beings), so many hedge wizards may not have dealt with anything Might-y enough to warrant a very large array of alternatives.
In addition, given the typical hedge/rival approach to defense, attacks with common attack types that fail might be attributed to magical defenses; I mean, for example, if I were an elementalist who had never encountered a magus before but knew my foe had magic themselves and my fire failed to hurt them, I'd probably assume a fire resistance ability before I'd assume general magic resistance. So that's at least another round I'd probably waste on something subject to MR.
Of course, all else aside, these are Hermetic magi against opponents without Magic Resistance. When you get right down to it, for almost any magus who would actually put themselves out on the battlefield, a round or two will be all they'll need.
Agreed - hence the greatest threat being sahirs, whose militant wing already operates on a doctrine similar to the School of Ramius, because they know their Penetration sucks. Magic Resistance is no defense against a dagger of Damascus steel (ReTe robes aside), nor against the Purest Flame (for those without the book, that's an alchemically-enhanced fire) being touched to a magus' robe. (The magic of Islam is wonderfully subtle.)
A non or gently gifted hedge wizard could see about obtaining mounted, mundane, allies. Getting charged by even a small group of mounted knights will ruin just about anyone's day.
Well except that the target magus is getting +3 to soak from his familiar bond score and another +2 verse most weapons from Terram and +3 vs fire from Ignem. It can get worse for there if the magus uses that entire "enchantments in the familiar bond don't cause warping" rule.
Pure Flame does +20 damage nonmagically, just so we're clear. That +3 vs Fire is not much comfort in the face of that.
Sahirs don't have the variety of effects a magus can deploy, but they can be fairly scary as a threat to magi, especially when there's five sahirs to every magus.
) Or do you know some daimons that can help you in exchange for vis?