Think it depends a bit on the breed, my silkies are mostly fine but I used to have a problem with some other mixed breeds. You may have to find new homes for a couple or maybe build more coops and keep them separate. Sometimes they can really injure each other and just won't give up.
i have two roos that stay together with the flock, they are from the same clutch and have never been separated, another runs outside the group, now if i introduce a new rooster there will definetly be bloodshed, the extra rooster is predator bait and he knows it. If i didn't have the space I would take him out, but right now he serves a purpose, and he is also from the same clutch. The best ratio is eight to ten hens per rooster.
I agree with taking 2 roos out and putting them together in a bachelor pen. They will be fine if they were raised together. You can then try to re-home them or find someone who might want them for the table. It is always a problem with too many roos when you buy unsexed chicks or raise them from eggs. They are very hard to get rid of, and your hens' backs will be bare before you know it.
If two are fighting religiously, it would probably be best to either separate, or get rid of the one that is getting beat up.
I've *mostly* had good luck with roosters. I try to either get them young or get roos that have been raised together. I have an older roo in my one coop and he is fine with other roosters as long as they are young. There are a few scuffles every now and then, but nothing major.