Uhmm

I THOUGHT IT WAS JUST ME!!! Hopefully it's because they're just coming back from their break, I really want Minchan(red hair guy) to stay the same

Maybe because of the difference in their livelihood? Canon minchan works as a hunter so he would naturally have more muscle. AU minchan works as a poor cook so it would make sense if he had less meat on him given he works late every day