my brother has 2 xingu 1's and 1 sveni in the same tank but he grew them up from 1 inch together. but they all did team up on his two peacock bass and kill 2 of them. yet he has 2 yo yo loachs in the tank and they dont touch them. pretty funny
aside from pikes not liking other pikes. i also thought i always noticed more aggression to fish that could be deamed competitors like other cichlids. i always seem to see m cichlids show aggression towards one another but never the like sd's or tinfoil barbs
I have 2 7-8in vezns with a 5-6 in female orange. They have been together in my 300g for about a year now with no problems. They are with a large blk aro, FH, SDs, chocolate cichlid. I also have some rock work and drift wood so they have places to claim but also lots of activity to keep them busy with Their tankmates.