It is likely that my input is simply anecdotal, but.....
About 6 weeks ago, I had a chicken, just decide to join my flock. I don't know if it was a feral chicken, who liked the idea of regular food, or if it was an unwanted bird, that someone "locked out" of their flock. But, a red Speckled Sussex (I believe) one day just appeared, when I let my laying flock, out into their rather large pen (75'x50'). Apparently the day before, it must have hopped the 5' fence around the pen (5-6 of my hens do so nearly every day). It might have even done so, 2-3 days previous. But, 4 days prior, I saw it, loose, took photos, and figured I'd talk to the neighbors.
Well, that day, that I discovered this young, yet seemingly, nearly fully matured cockerel, I took the photos I had, to my neighbors, and asked around. Nobody knew whose it was. So, I figured that I'd keep him around, to trade off, or make him the guest of honor at a Sunday Chicken Dinner. Now, I suppose he could be a capon, but, why would anyone caponize, then let go of a very docile bird? That all said, he has a very small straight comb, and small wattles. So small in fact, that I believed him to be a pullet, until it was pointed out that he has pointy hackles and saddle feathers, as well as a single sickle feather.
I have two very assertive roosters and one aggressive one. None of them seem to bother with this youngster. No challenges, no fighting, no chasing away. He mixes in easily with any of them. So, given the size of his comb, as compared to what my other three roos combs were, at his age, this may be a valid consideration. He certainly doesn't seem to have the temperament, of a typical rooster, if there is a typical temperament.
I'd say it's a theory, worthy of closer consideration.