yeah man, i had my 6 inch green and 5 inch gold sev in a tank with a green terror and some other cichlids and NOBODY messed with the green one, a few chased the gold only cuz he was a wimp.
well to be honest texas cichlids are one of the "bullyist" fish you'll ever own. i had two 2.5" texas cichlids that were messing up my 6" argentea and 5" gold sev. I swapped all that out a long time ago though and started over. now aside from my big fire eel i have allllll small fish. but i just got 2 1.5" green sevs and 1 1.5" red-faced sev. and really excited about those guys growing up cuz they're practically babies now.
first of all, nice fish man.
second, the gold sev i had was taken from a tank that was OVERFILLED with flowerhorns, red devils, etc. and he was just fine in there.
My male Severum bullies the heck out of every fish that won't put him in his place. But my sweet female Severum doesn't bother anyone-not Tetras, Gouramis, Corys, no one. All the other cichlids pound her though so she gets the 6' tank with the Plecs.