I think young roos are much less likely to crow if there is already a roo in/near the pen. That way they are less likely to draw the attention of the older roo who may want to do battle.
My Sebright pullet was the sweetest bird I have ever had. She would hop into my lap and I could carry her around under my arm all day long. My roo (Peapicker) started out that way and my pullet (Henny Penney) was the one stand-offish. After a while their role switched. Peapicker was never mean and he never crowed much until I sold my Cornish roo...my Salmon Faverolles didn't either until the Cornish was gone even though they got along fine together. I was surprised at how well that Cornish got along with all of the others and was much nicer to the hens.
My Sebright pullet was the sweetest bird I have ever had. She would hop into my lap and I could carry her around under my arm all day long. My roo (Peapicker) started out that way and my pullet (Henny Penney) was the one stand-offish. After a while their role switched. Peapicker was never mean and he never crowed much until I sold my Cornish roo...my Salmon Faverolles didn't either until the Cornish was gone even though they got along fine together. I was surprised at how well that Cornish got along with all of the others and was much nicer to the hens.