I think the problem is class variety. When you play Fire Emblem or some Dungeon Crawler, the stat spreads vary a lot and this helps. Stuff like a type of mage with high DEF but low WIS or a class of warrior that has low DEF but high WIS. Subverting common stats like that can be deadly on two ways since usually you expect warrior types to withstand physical attacks and mages to resist magical ones. Which can make Archers a bane to Mages and vice versa. Then comes a Dark Knight with good DEF and MGI but low WIS and that throws your common sense out of the window. He will go around felling warriors and archers alike tanking what is thrown at him, but it's a mage that could take him down in spite of being a fellow magic user.