I have the same situation - one head rooster, plus 2 junior roosters from the same hatch. They did their fair share of posturing, and a little actual fighting between the 3 of them, but mainly just the 2 younger boys against each other. I only ever had to do a little doctoring one time.
Somewhere between 1 year, 1 1/2 years of age, they calmed down considerably. There's still a little chasing, but no one is getting hurt. My birds free range most of the day; I also have 2 separate runs - all throughout this journey, I have never hesitated to separate anybody who's acting like a jerk. Either they go in the ICU run by themselves, or I bring the flock back in to the main run, and leave the jerk out to free range by himself for the rest of the day. All roosters are well-behaved otherwise, great with people, and all the other animals; maybe they just don't have that hard wiring for fighting like some have.
I'd say you could give it more time, to see if the hormones even out, but there are no guarantees they will mellow with age. The guineas could be part of the problem, too. Have you tried housing the guineas with the Maran for awhile, see how that changes things?
Somewhere between 1 year, 1 1/2 years of age, they calmed down considerably. There's still a little chasing, but no one is getting hurt. My birds free range most of the day; I also have 2 separate runs - all throughout this journey, I have never hesitated to separate anybody who's acting like a jerk. Either they go in the ICU run by themselves, or I bring the flock back in to the main run, and leave the jerk out to free range by himself for the rest of the day. All roosters are well-behaved otherwise, great with people, and all the other animals; maybe they just don't have that hard wiring for fighting like some have.
I'd say you could give it more time, to see if the hormones even out, but there are no guarantees they will mellow with age. The guineas could be part of the problem, too. Have you tried housing the guineas with the Maran for awhile, see how that changes things?