i think there are too much pressure on healing spells that makes mages useless as healers.
warriors
- tained- best damage way
- divine- bonuses to blocking and resistances (buffs for whole party - only useable in party)
mages
- tained - best aoe spells
- divine - best party healing spells also can power up damage of party (buffs for whole party - only useable in party)
rangers
- tained - best dps spells and additional aoe spells (burst arrows, infernal bolts, power bolts are only conjureable by taineds)
- divine - can heal party with half of strenght of divine mages and cast special buffs due to which you miss into target less - useable only in party -
Also important thing is to separate rangers from begin blocker, I mean you can't wear all the shields, for example rangers can wear max dragon shields. Mages can wear only up to dwarven shield, warriors can wear all the shields etc.
Description who can wear what:
Weapons limits:
Warriors can wear all melle weapons, they can wear only spears as distance weapon, they cant wear any of mage's weapons.
Rangers can wear all the distance weapons, they can't wear any mages weapons, they can't wear any melle weapons better than:
-clubs- skull staff
-swords- bright sword
-axes- noble axe
Mages can't wear any distance weapon, they can wear all the mages weapons, they can't wear any melle weapons better than:
-clubs- darmanian mace
-swords- jagged sword
-axes- steel axe
Shields limits:
Warriors can't wear mages spellbooks as shields.
Rangers can't wear mages spellbooks as shields, they can't wear better shields than dragon shield.
Mages can't wear better shields than dwarven shield.
equipment limits:
Warriors can't wear mages equipment and rangers equipment
Rangers can't wear mages equipment, they can wear all the rangers equipment and can't wear better warrior equipment than:
-helmets- crusader helmet
-armors- blue robe
-legs- crown legs
-boots- they can't wear steel boots and guardian boots altough they can wear draken boots.
Mages can't wear rangers equipment, they can wear all the mages equipment and can't wear better warrior equipment than:
-helmets- steel helmet-
-armors- plate armor-
-legs- plate legs
-boots- they can't wear any boots that gives 2 or more def (if they are not for mages only)
Altough im not fully sure about equipment section, you can ignore it if you don't like it.