I think we need to rule how our group want to handle Wards like the usual circle magic and the Aegis.
When I played the last time I think the general concense was that Aegis and the circle wards have to penetrate and so it is better to use lower level versions of them.
But there diverent "house" rules around that go down till the point where both have not to penetrate.
For the circle magic I personal would suggest the broad Vim based wards against demon, fearie, divine or magic might creatures need to penetrate and the more limited versions of the other forms not to give reason to have them.
Although for broad circle wards that go over all 4 type of might like against animal or ghost I think we need them to penetrate also.
Aegis should at last not need to penetrate to keep creatures of might outside.
So if I understand your proposal correctly you would say that:
1.) A broad vim-based ward that keeps out an entire category of creature, e.g., Circular Ward versus Demons or Ward Against All Faeries , WOULD need to penetrate;
2.) A narrow ward that keeps out a smaller category of creature (I'm only aware of such wards for faeries, e.g., Ward Against Faeries of the Air) WOULD NOT need to penetrate; and
3.) Aegis of the Hearth WOULD NOT need to penetrate.
As I understand points 1 and 2, you argue that the narrower spells ought not require penetration, otherwise no one would ever take them, but would instead just take the broader vim-based spell. (Not necessarily true, IMO, since someone with a high Te and low Vi might want to take Ward Against Faeries of the Mountains, in the right circumstances, for example.)
I'm not sure I understand what you mean about animal or ghost wards going against all four realms. Are there really magical ghosts and faerie ghosts and divine ghosts and infernal ghosts? I thought a ghost was a ghost. And while I can see that you might have a magical animal and a faerie animal, I wasn't aware of any ward that purported to protect against both.
I'm curious as to your reasoning behind why a broad vim-based ward would need to penetrate, but the Aegis would not.
Your proposal would certainly make a higher Aegis possible.
Circle wards can hold for ever without vis investment especial if the circle it self is build instead of just drawn while Aegis need more time, need to be redone each year and need vis investment.
Also I find it a bit strange it a creature of might can enter the Aegis but many if not all of its powers would fail at the very moment it enter the Aegis.
Let say a Might 25 creature fly into a lvl 25 Aegis that only have a penetration of 20, would't the flight power without penetration end in the second the beast enter the aegis?
About Ghost and Animal there I missremembered as the warding circle spells specifical say it only affect creatures of magic might. But there for sure also Ghost with Divine Might, one type is mentioned in RoP:D 133:
Personally I think it adds complexity needlessly, above ad beyond the complexity added by having wards need to penetrate in general, which at least has reasons both in terms of RAW and play (it slows power escalation by demanding penetration)
It being the complex proposal of the OP. I would suggest going with both need penetration- a might 60 dragon is supposed to be a very big deal, and it is much more so if you need a level 60 aegis with 60 penetration to keep it out than if you just need a level 60 aegis. It also gives a bit of a strategic issue- if we have the capability to get 80 levels do we go with level 40 with 40 penetration, of level 60 with 20 penetration- allowing things with might 20-60 to enter but with curtailed power or keep out everything 40 and below but giving 40-60 free range...
I agree that the original proposal was overly complex. I would be satisfied simply to say that all warding spells (including the Aegis) need to penetrate.
OK because we want to go the penetration all the way for wards I will go with a Aegis of 25 even if I think the penetration in our aura would "only" be 24 at 1203. I probably also will look how high I can get in inviting a duration sun Wizard's Communion within 1 season in the next years.
Because it was the status where I left my character at the time of writing the posting and with now 10 1/2 years left that are quite packed I doubt I manage to get this 1 point via a ability or art increase in this time.