I think the problem could be solved with random loot that has a slight to moderate lean toward the skills and stats of party members. Game detects that Character 1 has high intelligence, high aeroturge, low strength, and gives a boost to rolling a staff or robe that the character can use. Unless that's already in the game? Now that I think about it I don't think I've found *any* decent bows, and none of my characters are rangers.
I haven't had too much of a problem at the moment, but I can see it being an issue in the future. There have been short but significant periods where I've had a character in desperate need of a weapon upgrade that wasn't forthcoming, and it can set you back a tad.