I think when your Butti gets a few more inches on him, your stock will likely whittle itself down to- 1 buttikoferi.
Given the size they get to, the butti will outgrow the tank, and the other fish won't be a match for him. I have kept a large butti in the past, and it was a killer, had to be kept alone after a certain size.
If your red devil and dempsey get along, you are lucky. I would re-home the Butti and keep the other fish. Water also looks cloudy to me, possibly from dense stocking of fish. Your fish do look healthy though! Nice red devil for sure.