I love it when Selzar makes a thread with suggestions in it but doesn't put it in the suggestions forum.
Anyway, no, I finally realised this would be bad because...
Warriors can use a talisman to focus the magic and cast spells
Priests and Wizards can both use tools and weapons. I mean, who cant?
Barbarians can use talisman to focus magic.
There are many different combinations, and when you think of it logically, they all work out.
The only think that makes each class different is at the early levels.