Well, one of my 3 hens is definitely a roo. He is fancier from head to toe, bigger, keeps the others in line and struts.
The three of them sleep together, eat together, walk together and steal each others grape treats all the time. So fun to watch. Anyway he has not crowed, though he did make a quiet type sound similar to a crow it never developed. hope to avoid this as he will have to go if he crows.
I looked up how and why they crow and think I just might avoid it:
They crow to attract the hens,
They crow to call the hens
They crow in response to another roos crow.
They crow to prove they are boss.
Any way none of these situations are present in my backyard. they are like one unit all the time a cute little family and so fun to watch.