I agree with Shrapnel in that Custer and his men probably didn't have a choice for their last stand location. My guess is that they were overwhelmed, started to retreat, had that "oh schit" realization, and then it was every man for himself.
A bigger picture aspect was communication or lack thereof. If I remember correctly, there was supposed to be a three-way pincher movement with Terry from the north, Crook from the south, and Custer from the east. Did Custer know that Crook got whupped and wasn't coming up or not as fast? Did Custer jump the gun, thinking be could take advantage by surprise? Custer may have had better knowledge of his adversary if he knew what happened to Crook. And Terry with more knowledge of events may have updated the plan.
In any event, Custer was a hard-charger, needed in war warts and all, aka Patton, etc. That the research, discussion and interest still today is a testament to him and history. It was tragic, the good guys don't always win or maybe leaders don't always make the right decisions. However, that event, was probably the catalyst for a focused effort to end the Indian wars.
