Saw on a Facebook group that Frederic C. Wagner III, author of The Strategy of Defeat at the Little Big Horn, passed away on Sunday November 27, 2022.
I have found his books on the Battle of the Little Big Horn, quite informative and well researched. His analysis of the battle does not criticize or hero worship Custer.
If you have an interest in the Indian Wars of the Northern Plains, his books are well worth taking a look at.