As the infamous hatcher-of-Roos, I can add my few cents of anecdotal information to everybody else's positive reports.
After the one gloriously dramatic fight between Kellogg and Carl (no damage whatsoever, just the name-calling, crest-flaring, high-jumps with spurs forward, some feather loss) Kellogg/challenger stays the heck away from Carl. If he gets close, Carl rushes him and he skedaddles.
But I have many more roosters, and they all get along. There are some stare-downs with crests flared, mostly between the banty roosters, but it's usually just for warning's sake. Quite a lot of the time, the subordinate LF roosters perch companionably next to each other on some handy place to watch the girls and doze. After all, there are plenty of other roosters to call the alarm!