[Psitticine]

I can see your point that like attracting like might be overbalancing the scales a bit . . . maybe if the backstory of the heroes offers a reason for them to join certain factions, but they are designed to avoid simply repeating the same strengths?

To recycle my somewhat weak example, say the Master Astronomer had scrying abilities and was a good researcher, but had no other Astral magic himself? His skills would still be useful but not in such a way as to unbalance things. It'd also make good "story" sense that he'd be attracted to an Astral power.

Perhaps a better example would be something like a fallen Marignon Paladin who, after having his family killed by the Inquisition, has turned against them and now seeks out Death magic wielders with which to align himself . . . he'd add an interesting flavor to a nation like Ermor (I can just see him waving the Rod of Death as he leads a charge of Longdead Riders) but not in such a way as to make things unbalanced.