I don’t try too hard to min/max (I mainly go for flavor and roleplay, basing characters off old D&D, CRPG, and EverQuest characters etc), but a couple suggestions I have is to avoid Water magic specialization if you’re on a dry map, and avoid Partisan specialization if you’re just playing vs AI. Neither one is outright broken (and both still offer usefull traits even if some of it goes ignored), but both are situational for different reasons. One example for water magic is that early on you may have spells like Kraken and Freeze Water taking up space in your spellbook–which is all fine and good unless you don’t have any water nearby, then it’s just dead weight and blocking something else useful. It’s not that huge of a deal now that you can reset your spellbook and draw new spells and skills to research, but they’ll still be in there somewhere waiting to pop back out and get in your way.
Now, several schools of magic offer spells that are situational, but Water magic just seems to throw a couple of them at you earlier on than the others, gumming up progress a little sooner than the others if you don’t need what it has to offer up front.
(As far as I’m aware, none of the following has changed in a recent patch, so it should still apply) As for Partisan, due to the way invisibility and stealth work vs AI in AoWIII, the entire focus of this specialization is more or less wasted everywhere but player vs player. In the most basic sense, it comes down to how the AI is allowed to see a player’s invisible units in order to compute pathing and and such–in addition to several other decisions that need to be made regarding taking and defending keeps and such. They’ll also see your units for several turns if you’ve moved across their field of view, even if you duck into a tile you’re invisible on and continue to move through such tiles. I don’t know the specifics of every single rule, or what and when it can see what it sees, but suffice to say, the partisan tree relies so heavily on these features that you’re more or less gimping yourself by choosing it when playing vs the AI because they’ll see right through it. You’ll be spending research for nothing, or at the very best, you’ll be playing a guessing game as to whether or not your moment to moment efforts are effective or in vain. And I personally hate trying to take the time to be sneaky if it’s all just gonna turn out to be in vain.
There are other skills and spells to learn from Partisan which are genuinely useful, but you’ll want to make sure the other schools of magic you choose for that game are such that they’ll be able to do most of the heavy lifting.
EDIT: I’m actually seeing a couple mentions in this thread (from yesterday) posted at the official forums that the Devs have been working on making it so the AI are more restricted in the units they can and can’t see, but at the moment this is just rumor. I don’t know specifics. Depnding on the changes they make (or have made) this would change the viability of several Partisan skills. Just something to watch for.