They are fine, There has been lots of conversation about the Black wolves/curupira being kept with other large fish and I have seen Larger lacerdae comm'd with other large fish. I am sure this new one is a lac group Hoplias so I am sure it will be OK. There is alot of space in there aswell, 300G+. They bump into each other, sit on each other with not even the slightest flare or raised fin.