I don't disagree with your take. That has been his issue since day one, granted the first 2 years he had no depth. However, I will stick to my take as that being their identity.It's not that. The players (particularly the guards) are worn out. This was a problem of insufficient recruiting.
Last night Indiana played 6 players off the bench for a total of 66 minutes. We played two bench players for a total of 24 minutes and Fox had 21 of those. Hawkins played the whole game (again), Mitchell missed a minute, and Christie and Garcia each missed 2 minutes. They've been doing this for awhile now. They can't afford to get too physical on defense and risk fouling out and they don't have the energy to go balls out on both ends of the floor for the entire game.
If they ain't making outside shots they lose cuz they don't have anything else. Their offense is and has been for three years now, generally 4 & sometimes all 5 guys out on the perimeter with the first guy with a good look taking the shot.