my lion has been with my dogface puffer, huma trigger and wrasse for a long time with not one proplem, i think if you keep everyone fed and happy you wont have a problem, at feeding i dump a bunch of krill, brine shrimp, squid, and some reg. shrimp, then i throw in the siversides for the lion and the grouper, i think the grouper is the more aggressive at feeding, i have seen him take a silverside out of the triggers mouth, no one as ever niped at the lion and he hangs out all the time, so just be careful but it can be done,
my angel sometimes chases the foxface but i was told that is more to try to clean any crap off him.
just my experience so far