Typical mating behavior between mature consenting adults.
The rooster dances for a specific hen. He lowers one wing and sort of circles her. This signals his intent.
The hen squats. This gets her body onto the ground so the rooster’s weight goes into the ground through her entire body and not just her legs. That way she can support a much heavier rooster without hurting her legs.
The rooster hops on and grabs the back of her head. The head grab helps him get in the right position to hit the target and helps him to keep his balance, but its major purpose is to tell the hen to raise her tail out of the way to expose the target. A mating will not be successful if she does not raise her tail and expose the target. The head grab is necessary.
The rooster touches vents and hops off. This may be over in the blink of an eye or it may take a few seconds. But when this is over the rooster’s part is done.
The hen then stands up, fluffs up, and shakes. This fluffy shake gets the sperm into a special container inside the hen near where the egg starts its internal journey through her internal egg making factory.
It doesn't always work this way. Sometimes the rooster does not dance. Sometimes the hen runs away instead of squatting. Perhaps she doesn't accept him as a worthy mate, perhaps she just wants to see how interested he really is. Sometimes the rooster just let her go if she runs, sometimes he chases her. Sometimes the chase is not much, sometimes it it fairly relentless. There is a lot of variety in this. As long as it ends in the rooster stopping or the hen squatting and not getting hurt I'm OK with it. Each chicken has its own personality and each flock has its own dynamics. The flock dynamics are based on individual personalities. Changing one individual can change flock dynamics, especially if it is a major player, a dominant rooster or dominant hen.
Maturity level affects that too. You don't say how old he or the others are but it sounds like he and the females may be pretty young cockerel and pullets, not mature rooster and hens. The females have a part to play in flock dynamics too. Pullets tend to mature later than the cockerels so when the hormones hit the cockerels the pullets aren't sure what is going on. The mating act is not just about sex and fertilizing the eggs, it's also about dominance. The one on bottom is accepting the dominance of the one on top, either willingly or by force.
There is another aspect too. Some females may squat for about anything in spurs or just spur nubs, but some females often expect the future father of their chicks to be worthy. This is especially true of mature hens. To be a good flock master a male needs to find food for his hens, keep peace in his flock, watch for predators, and perform other functions. To do this a rooster has to dominate his hens. How can he break up fights if the others turn around and beat the crap out of him? What good does it do to warn them if they ignore him? This dominance is not just about size. To me the best roosters can do this by force or personality, their self-confidence and magnificence just radiates out from them. The ones with weaker personalities are the ones that are more likely to rely on force.
An immature cockerel does not have this personality but his hormones are telling him to dominate, so he often relies on force. I've had a 5 month old cockerel that dominated a flock of mature hens by personality. alone, really rare. I had a cockerel that could not dominate the dominant hen until he was 11 months old, and that was by force. It took two days of fighting between them before he finally won her over. There can be a huge difference in personality and flock dynamics.
I think how much room you have is a component in behaviors also. The more room you have the more peaceful behaviors typically are. You can still have a lot going on even with total free range conditions, personality still plays a part. Your expectations also play a part in how you perceive these things. What to some of us are natural behaviors seem to others to be an outright disaster.
As someone on here once said, watching immature cockerels and pullets go through adolescence is often not for the faint of heart. Again, I think how crowded they are has a lot to do with that. Usually if they can get through adolescence and become mature adults the flock dynamics change radically and you have a very peaceful flock. Some people eave the cockerel with the pullets during this phase. Some people separate the cockerel until they all mature more. If you do that I suggest you wait until about half the pullets are laying, those are usually mature enough to do their part after they have started laying.
I've tried to explain my opinion of why they behave as they do so maybe you can use some of that to develop your management techniques. While some chickens never seem to mature, some males are so weak-willed that they can never dominate by personality alone, and some hens just can't accept the dominance of any male, the majority of the time you just need to be patient. As they mature they work these things out and transform into a peaceful flock.
Good luck and welcome to the forum.
I wouldn't worry.
