That’s too easy an answer. It’s far more involved than that.
There is. Far more than most realize. My Battalion did a staff ride with an Army historian walking us through the entire lead up to the fight. We saw the ground, we learned the circumstances of the decisions made by Custer, and we even got to fire the weapons he and his men used on the Crow Indian Reservation. We even did day 2 on horse back for a few hours to get a small idea of what it was like to be a Cav trooper back in those days.
Fascinating stuff. Custer may have screwed up, but there’s very little to indicate how he could’ve done better, given the circumstances known and unknown to him.