Michael Donahue has a very interesting perspective on the battle. I’ve read about 20 books on the battle and really never had heard of the theory that he came up with on Custer’s moves.
https://www.amazon.com/Drawing-Battle-Lines-Testimony-Custers/dp/0912783451
Seems like according to Donahue, he was hell bent on capturing women and children at the far end of the village and holding them hostage forcing a full surrender. There is evidence that a few skirmishes happened on the southern end of where the National Cemetery is currently located and as they were approaching the gathering of the old men, women, children, that Keogh’s line broke and they had to retreat in panic back to Battle Ridge to cover their rear.
Like you said, Custer didn’t anticipate the uber aggressive assaults from the Northern Plains tribes and thought they would just run. Even in his battles with them in 1873 & 1874 they didn’t run. He should have known better.
He also had no intel on the Battle of the Rosebud where Crook literally had almost twice the men that Custer did on June 25th and he still had to fall back. The Indians tried to pull the surround and wipe out maneuver in that Battle with LT. COL. W. Royal’s small cavalry contingent - and they almost did.
I love reading about the Great Sioux War of 1876. Always learn something new about it, no matter how much I read.
If Custer thought that he had the time, he would have delayed his approach march, maneuvered to get his columns to positions of mutual support, tucked in his trains, and take time to find out where the other columns were.
He did none of these things.
I have seen the same thing in combat and in training. Most commanders tend to think that any delay will shift the initiative to the enemy. Sometimes, that is correct, but sometimes hasty attacks become uncoordinated, piecemeal efforts that fail.