I have this rooster, Jared, top of the pecking order, who understandably does not like his sons (four total). Three of them, he chases them away from the food and kicks them off if they try to mate with a hen. This is all totally in line with how my chickens have behaved in the past. Even if a rooster tolerated another one existing in the flock, he would enforce chicken law.
Except one of them, named Hapsburg, doesn't bother him at all. Jared seems unwilling and possibly even afraid to attack him, and if Hapsburg manages to mount a hen, Jared kind of lazily jogs over and is disapproving but doesn't interfere. He still outranks Hapsburg, who runs away from him/respects him, but Jared allows him to eat/drink/sleep/chill with all the hens. And if Hapsburg is fighting with one of his brothers, Jared always chases away the other one.
It's as if Jared has chosen an heir to the throne, so to speak, which I would just think is cool and everything, except Hapsburg is literally the worst one he could have chosen. Hapsburg pipped late, needed help hatching, had an underbite i.e. the beginning of scissorbeak which mysteriously went away, has walked with a limp for no apparent reason his whole life, was very slow to start crowing, and at full sexual maturity still doesn't outrank at least two hens. (I mean, it is hilarious to watch when he's trying to do the dance and they're just going in a circle with her growling and trying to peck his head, but when even the hens don't think he's worthy...) I'm not sure if it's a coincidence, but Hapsburg does look the most like his father in terms of plumage, build, comb, etc. It can't be an age thing because all four cockerels are from the same hatch.
I just didn't think a prime-of-his-life rooster would choose a second-in-command with all rights and privileges, even if they look so similar some of the hens mistake them for each other. I was guessing maybe he's chasing off the healthier, virile males so that they'll get eaten by predators, and he's not worrying about Hapsburg because he can tell he's the weakest link and is already at higher risk of being eliminated, but as smart as chickens are I doubt that's Jared's logic.