harleyjo, you have to be sure your rooster is mature. A young rooster will be a problem for your youngsters. The age of the rooster should be at least a year and a half. I have raised gamefowl for many years. When my chicks are weened from their mom, I put them in a large pen with a mature cock to police them. Not only does this mature cock keep the young killers from fighting, but he is always very good to them, calling them for treats and acting like a dad should with both stags and pullets. I`m sure there are exceptions, but I have not had one. A rooster hatched last year might be OK if itwas early last year. Guess ya gotta try him and see.
I don`t think changing roosters every 18-24 months is needed. Maybe if you are producing eggs for a hatchery, but those operations usually change hens also to get the highest production possible. Most of us, especially with small hobby farms, will never need to be concerned with all that. Good luck.........Pop