I've got my delhezi in with some largeish rainbows, bristlenose plec, and an altocompriceps, worried about the comp in the future, but he's the only survivor of hurricane sandy so maybe he's tough enough.
I think this is more of an exception than a rule. How big were these fish? I own 20 polys and ive never had one that attacked a fish it couldnt fit into its mouth.
An exception, yes, but far from unheard of. My very first senegal did not like angelfish for some reason. I actually caught him(too late, sadly!) taking one for a death-roll.
Haven't seen African Brown Knife mentioned, they make good tankmates. My first senegal was bought as a tankmate for one.