Like most of the people above said, Minsc's lowish dexterity could be fixed with the "Bracers of dexterity". Those did not even need any backtracking, you just find them on the same map like Dynaheir (at least in BG1 vanilla).
He ended up as my best good aligned warrior for melee and ranged combat.
There were other good aligned fighters with more problems, like Ajantis:
No dexterity bonus for his AC and lowish strength for a dedicated heavy armor + heavy shield melee warrior.
Man, it was a pain how much this poor guy was hit and poisoned by the spiders in the forest
And lets not even start with Khalid