Yes, they’re fine. They’re not avian monsters. They just retain a degree of natural feistiness that has been modified a bit by man and is generally directed between mature males.
Using a dog analogy, pretend that a wild junglefowl is a wolf and a normal coop chicken is a golden retriever. Gamefowl are like malamutes, huskies, and other wolf-like dogs fresh from the far north. They’re tame. They can be fine pets. But they retain a hard edge that can let them survive in semi-feral conditions. They’re made for living in a pack. But the packs have a pecking order that is enforced by tooth and claw. They’re not cold blooded killers like wild wolves, but they aren’t soft goldens either. They’re in the middle.
Your gamefowl flock will have a natural pecking order. At the head is a mature rooster. Under him will be 12-20 hens or however many hens you keep. The hens will have an order among themselves. Chicks will grow up and male chicks will live under the domination of the mature rooster until they get close to maturity. Then they’ll move to the edge of the flock (if free ranging). They’ll finish maturing out of the view of the dominant rooster. Among themselves, a stag will become stronger than the rest. At the right time, it will challenge the mature cock and either kill him or die. Either way, life will go on for the hens.
Its just a natural order. Nothing more. Same thing whitetail deer, turkey, lions, gorillas, and many other species where a dominant male controls a territory and a harem of females until a new, stronger, male replaces him. The game drive, that fight instinct, is just a tweaking of that natural instinct by man to make the males stronger and fiercer fighters. But it doesn’t make them indiscriminate killing machines.
I’ve kept bulldogs for years of various breeds and lines. Some are crazy killing machines, made that way by centuries of selective breeding. Gamefowl are NOT the pitbulls of the chicken world. They aren’t drastically modified from nature to be sometime they wouldn’t be otherwise. Man’s selection just refined an animal that was already naturally aggressive so as to make the aggression last year round (which is, by the way, why domestic chickens lay eggs much of the year and not during just a breeding season, the same modification that made roosters fight year round likely made hens lay year round), and for the aggression to be more enduring.