Cannabalism in most snakes, those who are not naturally snake eaters, is almost always because of feeding and returning the the common cage too soon or while one snake is still hungry. How many time have you seen males slamming and how long did it last? Are you SURE they were males?
I've kept boys together. I've kept, am now keeping a trio together that have been cohabbing for years, females together. I've kept mixed pairs and trios and large groups together and have never in over 25 years and hundreds and hundreds, thousands most likely, had an incident of one eating another. Same for corns. Same for milks. Same for FWCs. Same for Rosy Boas. Same for Sand Boas. Same for Pacific Gophers. I'm sure there are others, but I think that makes my point.
There are exceptions to every rule, but an exception is just that, an aberrancy in the norm, NOT the norm.
donna has had this explained to her multiple times.