I'm looking to add a 5" African Knife to my tank currently housing a couple of 12" Gars, 8" Afrowana, 4" NGT, 6" Chinese perch and various 6-8" bichirs, would this work out?
I would be concerned about the Gar. While you do have a small NGT, it's dorsal spines are a good deterrent for some fish. The Knife would be vulnerable.