My large fowl hens laugh at the bantam roosters and won't let them mate.. for the most part.. Given the choice, they ALL choose the large fowl rooster. Being raised separately.. most the ladies would not submit to the bantam boys antics and this resulted in him sneak mounting them. When raised together.. most large fowl hens will never know the difference and naturally more easily accept his dominance.
Bantams are NOT any more gentile on hens than large fowl roosters. They are smaller but they have the same size fight in that tiny package.
No the amount of mounting and mating has nothing to do with size of the rooster and everything to do with individual personality.. sometimes influenced by age..
young cockerels may mount excessively because it's about dominance more than mating and they often have something to prove. Time of year can influence this.. spring time with daylight increasing makes hormones surging and rushing.
Young cockerels can be especially rough as they learn the ropes and try to hang on for dear life.
Bantam crowing is a little higher pitched but just as loud and can be more annoying.. in my OPINION.
I have successfully kept even two roosters with only five hens and NO over mating.. Everything will depend on the individual, plus flock dynamics, set up, and so much more.
I have seen one rooster kept with 20 hens and a few were over mated.. because they do have their favorites. Numbers matter some but it doesn't tell the whole story!
Roosters (mature) are handsome, and hilarious when they are well balanced. I love having them in the flock. To see them tidbit to the ladies, and drop their wing to do a little shuffle dance, or to let the young chicks warm up under him, and of course standing tall watching the skies while the ladies do their own foraging or dirt bathing, they escort the ladies to and from the nest box for laying and even help them search out new nesting sites!.. it's all quite entertaining and even inspiring.
I've been attacked by a few boys.. both large and bantam fowl. Some are just nasty towards people. Many folks put up with it from bantams because it hurts less.. but they are JUST as freezer worthy as any other chicken. Some have come after my dogs from across the yard, while others tolerate the dogs catching a frisbee right next to the flock. Sometimes it takes going through a few to find the right one for YOUR flock.
For me.. Rooster's don't equal protection against my local predators but more often front line sacrifices as they are simply no match. A head hen also performs predator calls to warn the flock. I personally would not add one to a peaceful flock unless I was planning to breed/hatch or REALLY wanted that eye candy on pasture and don't mind the 12, 2, 3. 4, and 5 am crowing oh and noon and two pm.. it never ends and is NOT only at dawn.. since they crow for many reasons including to warn would be predators, communicate with other roosters, show how virile they are, and so on. You do get used to the sound eventually and it blends into the background. My neighbors are far enough away even when they're sleeping with windows open that it hasn't been an issue for me.. and the middle of the night ones are not *usually* relentless and a random crow here or they may disrupt sleep but maybe not enough to register that's what happened.
Ultimately it's complex, and it all depends on your flock as well as the individual.. I'd rather have a large fowl rooster.. that way if he is too protect then he will have a better chance of it and if he does mate.. then my egg (and carcass) size in offspring would not be diminished or compromised. Bantam roosters just don't bring it to the table FOR ME, outside of bantam flocks.
I have kept many a bantam rooster.. They are lovely complex creatures very much
equal to their large fowl counterparts. They do all the same stuff, and are a BIT easier to handle, so I'm not against them.. I think they are fantastic, but not a better choice per say just a different choice.
How old are your hens now? Will you be willing to feed a NON layer feed (with oyster shell on the side) if you add a rooster.. or would he be eating "layer" feed? Is there a specific reason you're thinking of adding in a rooster? DO you have plenty room for another chicken in your set up/coop/run/range? Are you allowed to have a rooster in your location? I only ask in order to support you towards YOUR best outcome possible!
Happy chicken adventures!