I am not sure this is even worth two cents....but here I am.
I think they all turn when the spirit hits them. Roosters...they have a job to do. If you are perceived to be a threat they will protect their girls.....because that is their job.
So far all my RIR roos were dispatched.....to freezer camp and beyond.
My Barred Rock....he was the Lone Rooster that the BO beat up and I made him his own coop and run and found him some girls. Gosh, there has never been a better roo to his girls. He has five, two hens and three pullets. But he hates my guts. I made him the coop and run, I saved him from the BO and I found him his girls. I can no longer go in the coop and run.....unless I am dressed in my bib overalls and coat with the hood. It snowed and I went out there dressed like that and he ignored me....go figure. My husband usually goes in for the eggs and to feed and water.
My Buff Orpinton came at me once.....I was a perceived threat and understood it immediately and simply pushed him away with my boot. One of the hens escaped from the corner run and I was trying to catch her and put her back....BO thought I was hurting her when she made racket when I picked her up. BUT....my DH had a big run in with him a couple of times. It was getting ugly....all I could think of was the BO needed to back down because DH would dispatch him if he did not. He has not come at him again so maybe it was a glitch.
My cochin roo, Sweet Harry, has done nothing that could be considered agressive....to date.
But I think it is simply the rooster's personality and what they perceive to be a threat. We all want them to look after their girls but how do we know what goes through their minds.
Be careful always. Don't turn your back and let your guard down. And don't let the little ones be around them without being right next to them.......