Yeah, but the issue is that magic hits so hard that any decently well built caster you can make will easily one round even a "tanky" magic armor using foe, usually multiple depending on placement, and often kill or CC them after cutting through the armor. So you really only need one offensive caster, unless you want a support character. (I like having one geomancer/hydrosophist/pyro that literally does nothing but fortify, ice armor, haste, and teleport combatants around. Super useful for getting the warrior you just phoenix dived into a bad spot out, or keeping them alive.)
