" Can only use Equipment from schools he's trained in "
This would be a very elegant fix that stays true to the lore.
You're kidding, right? More and more equipment is going to be added to the game over time. Even now, who cares if the Wizard is restricted to other school's equipment? So, no War school armor pieces... but he still gets the torso piece that is attuned to his element (Leviathan Scale is coming, and I'm guessing Earth will also get a chest piece as well at some point), plus one of the arcane Cloaks... and then any of the enchantments that add armor.... What do you gain? He has several wands in school, and probably doesn't need any others. What rings does a Wizard usually use that isn't in school? Weapons? OK... so he can't use Eagleclaw Boots... what a loss. If absolutely needed, he can Tanglevine himself. Want a Regen Belt? Use Regrowth instead. There are plenty of alternatives that give equivalent effects for the lack of the few pieces of equipment to which he might actually care about losing access.
Here is a list of all the equipment the Wizard can currently equip that he would
lose access to with this change (including promos, since these will presumably matter down the road, let alone online):
[spellbook]
[spells]
Ankh of Asyra
[mwcard=mw1q02]Bearskin[/mwcard]
Chitin Armor
[mwcard=MWSTX1CKQ03]Colossus Belt[/mwcard]
[mwcard=FWQ01]Dancing Scimitar[/mwcard]
[mwcard=mw1q27]Dawnbreaker Ring[/mwcard]
[mwcard=FWQ02]Defense Ring[/mwcard]
[mwcard=mw1q04]Deflection Bracers[/mwcard]
[mwcard=MWSTX1CKQ06]Eagleclaw Boots[/mwcard]
Elfric's Life Ring
Eye of Bael
Faith Healer's Staff
[mwcard=mw1q11]Gauntlets of Strength[/mwcard]
Gloves of Skill
[mwcard=MWSTX1CKQ02]Hunting Bow[/mwcard]
[mwcard=mw1q13]Ivarium Longbow[/mwcard]
Leather Belt
[mwcard=mw1q15]Leather Boots[/mwcard]
Leather Chausses
[mwcard=mw1q16]Leather Gloves[/mwcard]
[mwcard=DNQ10]Meditation Amulet[/mwcard]
[mwcard=MWSTX2FFQ06]Morning Star[/mwcard]
[mwcard=MWSTX1CKQ04]Reflex Boots[/mwcard]
[mwcard=mw1q23]Regrowth Belt[/mwcard]
Resplendent Bow
Ring of Healing
Spiked Armor
Spiked Buckler
[mwcard=MWSTX1CKQ01]Sunfire Amulet[/mwcard]
[mwcard=DNQ07]Veteran's Belt[/mwcard]
Vorpal Blade
[mwcard=DNQ09]Wand of Healing[/mwcard]
Wychwood Ironvine
[/spells]
[/spellbook]
And he would still
have access to:
[spellbook]
[spells]
[mwcard=mw1q01]Arcane Ring[/mwcard]
[mwcard=MWSTX1CKQ05]Dispel Wand[/mwcard]
[mwcard=mw1q07]Elemental Cloak[/mwcard]
[mwcard=mw1q08]Elemental Wand[/mwcard]
[mwcard=mw1q09]Enchanter's Ring[/mwcard]
[mwcard=mw1q18]Mage Staff[/mwcard]
[mwcard=mw1q19]Mage Wand[/mwcard]
[mwcard=mw1q22]Moonglow Amulet[/mwcard]
Mordok's Tome
Repulsion Cloak
Rod of the Arcanum
Sistarran Robes
[mwcard=mw1q31]Staff of the Arcanum[/mwcard]
[mwcard=mw1q32]Suppression Cloak[/mwcard]
Wispwillow Amulet
[/spells]
[/spellbook]
And depending on his choice of element, he
could still have access to some of:
[spellbook]
[spells]
Cloak of Fire
[mwcard=mw1q06]Dragonscale Hauberk[/mwcard]
[mwcard=mw1q10]Fireshaper Ring[/mwcard]
[mwcard=MWBG1Q01]Gale Force Ring[/mwcard]
Leviathan Scale Armor
[mwcard=mw1q17]Lightning Ring[/mwcard]
Staff of Storms
[mwcard=FWQ10]Storm Drake Hide[/mwcard]
[mwcard=mw1q33]Wind Wyvern Hide[/mwcard]
[/spells]
[/spellbook]
And of course, only a Fire Wizard would have access to Dragonscale Hauberk, which makes the Wizard's choice of school actually relevant - as compared to, say,
some cases where the Elemental School choice was arbitrary.
I think the biggest impact this proposal alone would have is preventing a Wizard from wearing (1) Veteran's Belt or one of the regeneration belts, (2) All the Leathers (!), (3) Gloves of Skill (like a mini Akiro's Favor for ranged attacks), (4) Chitin Armor (no Acid resistance for the Wizard), (5) Eagleclaw Boots (Wizard becomes easy to push around), (6) Reflex Boots/Bracers of Defense/Dancing Scimitar (no equipment-based defense for the Wizard), ... and probably most importantly, only a Fire Wizard can bulk up on Dragonscale Hauberks (although all but Earth Wizards have at least one +2 armor chestpiece available, and even the Earth Wizard can wear Sistarran Robes and Elemental/Suppression/Repulsion Cloak).
So while this proposed "fix" is thematic and does something to make Wizards at least slightly less tanky by adding a drawback, I'm inclined to agree with DaveW that it may not do enough. Perhaps if this "fix" were approved, it might be accompanied by other "fixes" - like (1) cutting the Wizard's channeling to 9 (since he still has cheap access to more +Channeling spells than any other mage - might as well have incentive to use them), and (2) slapping "Epic" on the Wands (which hurts everybody to some degree but at least makes matches end eventually) and Wizard's Tower (...), and (3) making Arcane Zap a little less good (e.g. either costs more mana or loses Ethereal or has a 1-1 range restriction or can't target flying creatures or something so it isn't so darn good).