As a Hoosiers aficionado (I actually have shot hoops at the real Hoosier gym in Knightstown) yes, it was well cast. And every detail down to hair styles, clothes and cars were done well.
As for the players. Just some insight:
Jimmy Chitwood, The actor who played him actually never played HS basketball. He was cast when the director saw him at an open gym shooting hoops. But it is obvious he was an athlete, he was an All State golfer in HS.
Merle the point guard. Killed himself like 10 years ago.
Buddy, he did play college ball, but it was like at some NAIA school.
Rade Butcher, the kid who wanted to shoot, was the most accomplished, he played college BB at Division III DePauw (not DePaul). In typical NCAA fashion, because Butcher received money for the movie, he was suspended the first semester the next season.
Ollie actually played HS basketball.
But two of the cast never did. One was Chitwood, I think the other was the religious dude.
The only "actor" of this cast that I ever saw in any other movie was the guy who played Dennis Hopper's son, who had a small role in Platoon.