Well, I could lower the gem income from ~9 to some, say, much smaller number
.
But I do think they should each give two major bonuses. One of them is guarded by *tarrasques* and is probably a match for most national armies until the midgame.
Wizards are great for anyone, but a lot of indie mages are just not a big deal, depending on which nation you're playing. Likewise, some magic bonuses are very ho-hum for some positions.