If those four Clown loaches are already in this community, I think at least part of the answer is increase that loach group to 12+, enabling them to form a natural complex hierarchy and giving them more confidence to be active.
From the Mochokidae group of catfish, I'm struggling to come up with many safe shoaling candidate species that could be combined with the likes of adult Oscar Cichlids. The best I can think of would be
, MatsP on here has my old singleton and has since acquired another three.
I've very recently acquired a second
, but the newcomer is still in quarantine, so I've yet to see if multiples make them less reserved first-hand. However, going on my eldest one raised from a ~3cm SL youngster, they are not exactly vulture-like at food time when compared to the likes of my Giraffe Catfish for example!
Dreaming of a full-on 5x2x2 Zaire River rapids biotope...