Hey there and welcome to AA! I have had problems with the CAE
and angelfish. Came home one day and found 2 of them finishing off my golden veiltail. I wasn't sure if it had died and they were capitalizing, but later I watched them try to attach to one of my other angels and they were out of there! I don't think the rainbows would hold still long enough to get hurt, but gouramis and angelfish might. Also, I had the CAE
in there for several months with no problem but once they started getting a little bigger, they got a lot more aggressive. Good luck and sorry for the essay!