LOL! Sorry to laugh at your frustration. I just can sympathize. I honestly don’t know for sure why they won’t molt at the same time, but I sure wish they would all get together and put it in their datebooks!. Geesh!!
My understanding though is that the molt is hormone related. So though it can be weather and seasonal related as their hormones will kick as a reaction to those things, bunnies inside with the same inside temps, same amount of light, will also molt about 3 – 4 times a year. So in your bunnies cases, one may have molted, the other picked up a scent difference with the hormones and by the time the one bunny was finished, the other bunny’s body was reacting. (again though, that’s just my best guess as to why one would do it right after the other)
hang in there – brushing daily does help. I also keep a wet washcloth near me to wipe my face while I brush or all the fur tickling my nose will make me go crazy.