Merddyn
Scholar of the Arcane
Amurites weak ? Is there any other civ able to spawn mages as fast as they do ? With my clan of embers I have to wait many turns before my adepts can promote, and during that time they just sit around in my cities (apart from haste, and other minor spells).
Being able to produce directly mages with fire2 or wind2 seems like a good enougth advantage during mid game, even if they could use a little something during the early game
Not as hard as you think, though; All you need to do is get the Form of the Titan, a Great Commander for the +2 experience version (You can get a GC from getting a tech soon enough), and the three +2 experience civics; I did that last game, and I was essentially able to "build" mages. All my adepts started with 10 experience (and as I was playing the Sidar with a good number of Great Engineers, they got completed in one turn... Plus I had a really good coin income. Aaaanyway), so as soon as they were built I could promote them to mages.
By the way, 10 mages casting fireball at once? That's some scary stuff right there.
Edit:
On Summoner trait - I don't think it's a problem by itself. It's Summoner + Puppets that's the killer combo. Keelyn + Sorcery will crush anything at similar tech levels in my experience.
Here's an idea, (I've never played Balsarephs to know if this is already true or not, as my friend always plays them) why not make it so that creating puppets costs gold? Perhaps 1/3 of the cost to upgrade to whatever unit they're making a copy of? After all, I doubt there are no materials to create a puppet, and even if there are, could be something like material components in D&D. That way, the puppets, and the ability to make them isn't weakened, but the frequency of making them is limited. Also, the player has to have a good gold income economy to field them frequently, which also reduces their science rate, making it harder for them to get archmages if they're using them earlier on, and at the same time, to be able to upgrade to archmage, they have to hold off on their puppet creation for a time.