Jules Great answer, thorough and compassionate and I completely forgot about Ice storm...
With that said you have some great points about Mages. I see why their costs are so high because they have dual purpose but as you said " A Few RT's can take them out" I like the proposed changes, but I propose leaving them be, but making them invincible on defense.
If you have Mages home and you are attacked the Mages can conceal themselves in their towers and avoid all enemy damage
I believe this will solve your issues with the weak defense and give Elves a chance to survive if you continue stacking them to the level the Elf needs to cast and defend themselves. Keeping their Gold upkeep the same, balances them so people dont go 100% Mage armies and just farm.
Also it might be a good idea to start housing them in Guard towers (Or Schools) to make those more efficient since guard towers only work on defense.
If we are going to follow lore, ranged units cannot be range attacking Elven kingdoms without some kind of handicap. Too many Trees and whatnot....
For their upkeep, it seems high but I feel its close to what it should be. Maybe drop the food to 1 (or even 0) as Mages can conjure food up.
I like this conversation!
