Too many mages?

[Executor]

Not sure what items or why you're forging them?
Mages rarely need any items besides the occasional booster or penetration item and such, no point in giving them anything else as most of the time it won't protect them.

As for gems, it's best to carry a scout with gems and place them on mages when needed, when you're facing a real battle and such, rather than to let the AI waste the gems pointlessly. Subsequently, I also hope you're scripting mages since the AI does a rather poor job.
Personally, I find it expensive, dangerous and wasteful to carry gems and items on all mages. I suppose it not that risky in SP but in a MP game you'd make those mages a big fat target for slaughter.

A far better investment would be to use the gems you're placing on mages to summon some thugs, a bane, bane lord, sleeper, and use the items you've forged for the mages on them instead. A 20 gem investment in a thug can do far greater damage than your troops.