Floyd was arrested on March 20 or 21, during the semester, before spring ball. Being his third alcohol related offense, and assuming Kelly/Notre Dame would have to deal with this relatively quickly, it made sense to suspend him from spring practice. Then he could deal with the legal issues and work on the conditions given him to get back on the team. Good plan, based on the timing of the arrest.
Rees and Calabrese were arrested on May 31. Schools out. You can't suspend them from summer practice since there is no official practice. The next option is the fall. If you suspend them from fall practice, they can't possibly play in Ireland anyway. Missing a game seems inevitable either way. Good plan, based on the timing.
Seems fair to me, especially based on the timing of the arrests. I personally would have liked for them to be suspended for the summer, even if it didn't mean much, just to be consistent and look more proactive in dealing with this stuff.
I also don't buy the argument that a player would get treated differently based on their skills at all. That's not Notre Dame, that's not Kelly.