Gathering intel for a possible war comtrav ?
Please do, it will make the game more interesting.
I actually have more or less the same problems, and solved them by not casting those spells at all. Using the few attack spells (usually 2N or 3E needed, like blade wind, wine arrow, sermon of courage, breath of the dragon, panic, sleep cloud...) seems to work better for me, and I wait for battlefield-wide spells to protect the armies I control. That means, alteration is your priority if you want to rely on maenads to attack anything : mass protection, then army of lead and gold.
Protection magic, in my opinion, is better used for making thugs. Like invunerability : making your pans thugs just means giving them items that increase their defense, regen, and reinvigorisation, cast invulnerability on turn one, and you're faced with a defense 25+, protection 30+, regenerating thug. You can also make him berserk for added morale.
Before that, Maenads are your protection. You don't need spells to defend them, you need them to prevent your real offensive units from dying. Your units could be anything : centaurs, carrions, satyrs, minotaurs... it doesn't matter.
Also note that getting one or more air spellcasters to use "anti-arrow" spells increases the life expectancy of your maenads armies by a lot, since arrows are one of their biggest weakness. And you've got one right in your paths : fairy court. Which also makes pretty good free summonable "archers" of their own.
All of this sounds like pretty much middle-game strategies though. The gorgon, good diplomacy (difficult to achieve in a SP game
I know) or plain luck will help a lot.
PS : Legion of steel works only on armored units if my memory is correct, and maenads, being naked, of course, can't use it.