I used to have one largish (8-9" ?) banded Leporinus, and in the same tank there was a similar size stripped Leporinus (L. cf arcus), a green severum, a Distichodus lussuoso, and 2 headstanders: a stripped (Anostomus anostomus), and a marbled (Abramites hypselonotus). So everybody was SAmerican except for the African Distichodus. Tank was a 150g.
Most fish in there are what one normally considers 'jerks' and each adhered well to that motto. However, together they seemed not to bother too much each other, and no deaths or serious injury (not even much fin injuries) occurred over several years. The boss (read, the meanest) was the Distichodus lussuoso. However, the ones who won everything in that they could bother others but not be bothered themselves were the two headstanders. They are just too fast and snicky. The Leporinus arcus and the severum were the chillest.
I don't recommend recreating this ill-structured community. However, it developed over time because I either inherited mean fish others didn't want, or I made not-clever purchases of little babies who grew to monsters. But I enjoyed it and they became a sort of stable unnatural community.
The genus Leporinus contains many species and although most are omnivorous and hence eat anything available, most species have a strong preference and need for plant material of various types (seeds, leaves, roots, fruit). But they have no qualms about eating animal protein (insects, crustaceans, worms, fish).
Beautiful fish, not the easiest to keep.
