There really are some sweet roosters out there. First I would make sure that is what I had, especially if you want to breed from them, you would really not want to breed an aggressive rooster as there can be a genetic component to behavior. Then I would let him/them with the girls, especially if you are free ranging them. A good rooster will offer some protection to the flock or at least be a warning system so the hens can hide or get away in case of trouble, often why a rooster is lost instead of a hen.
X2! Find a strain where the roos are nice and cull any mean ones mercilessly. I have a 2.0 (not zero, LOL) tolerance policy. A roo can flare and challenge me twice, then he will never breed any hen in my pens ever again. I have 300+ chickens and get about 1 mean roo per year. The rest are either wary of me, or tame enough to be handled easily, and I am around them and in their pens daily. My teenage niece is much more timid and she also goes into the pens daily and no roos ever challenge her either (they would not get the second count if they ever went for her).
I do not agree that a tamed rooster will be more likely to turn mean. There is much more to their personality than that. My sweetest roos are 2 Rhodebars that were raised by kids and taught to sit on their shoulders like parrots. Neither has ever challenged me, one bit me last week when my hand was between him and the food that he wanted really badly, but that was obviously bad aim, not malice. Once I caught and treated all their hens for lice, stuffing them into dog carriers as I went. The roos were clearly upset by me taking their ladies, but neither tried to intevene at all. They will remain my main Rhodebar breeder roos for a reason, they are so easily managed. Every breed I have is similar in temperment (I avoid Orps and Wyandottes/Rocks for exactly this reason). I sell chicks to families with kids, mostly pullets, but if they choose to have a roo I want to be able to say it will be very unlikely their pet will go to the dark side, even if they tame him.
Not everyone will agree with me, but it works for me and I have never had a customer return a roo because he was mean. Roos should be gentle as the norm, if yours are not, start over with a breed/strain that have known good temperments, you will be very happy with the results.