Thanks for the clarification. You have three cockerels and two pullets that are four months old. When they go through puberty the hormones typically drive the cockerels to be real beasts. They try to mate the pullets that don't want to be mated and they often fight. That is hard for some people to watch and it can be violent. Since it is often violent occasionally some chicks can be injured or even killed. I don't know how much of that fighting or mating behavior you have seen.
I let my cockerels and pullets grow up with the adult flock until butcher age, which for my cockerels is typically 23 weeks so they have gone through puberty with the pullets. Once every three or four years the boys get rowdy enough that I separate them from the pullets, but the other years it doesn't get that bad. Like 50-45-1, some years I hatch a lot more cockerels that pullets. Other years I hatch a lot mote pullets. I have noticed (because I pay attention) that the ratio doesn't matter, it's how rough certain cockerels are. I typically hatch a little over 40 chicks a year so you can see the scale.
One huge factor is how much room you have. That's why it would really help us to know what your facilities look like and how big they are in feet or meters. I find that having one rooster with the flock doesn't take that much more room as long as he is a mature rooster, but if you have more than one the space requirements go way up.
What are your goals for those cockerels? Why do you want a rooster? The only reason you need a rooster is if you want fertile eggs. Everything else is personal preference. Nothing wrong with personal preferences, I have some of my own. But those are wants, not needs. I typically recommend you keep as few males as you can and still meet your goals. That's not because you are guaranteed problems with more males, but that problems are more likely. Three cockerels with two pullets is not likely to end well.
I don't believe in magic numbers, whether it is square feet per chicken or the ratio of females to males. People with one rooster and over 20 hens can have the same issues as one rooster with two or three hens. Sometimes there are not any issues. When you have multiple roosters it gets even more complicated. Adding more pullets is unlikely to solve the basic problems, though if you have enough room so each male can establish his own territory out of sight of each other and keep his own harem it is usually not bad.
So what are your options. Getting them through puberty is your first goal. You can leave them together and see how it goes. I like to base my actions on what I see going on, but I'll have 40 chicks, not 5 and a lot of room. Definitely have a Plan B ready. For me that would be a separate facility where I could isolate all or all but one of the boys from the girls. This separation could be temporary until they grow up and you can try to merge them with the pullets or it could be a permanent separation.
Depending on your goals, you can get rid of all or all but one of the boys now. You can eat them, try to sell them, or give them away.
I don't see a lot of other options. I will repeat, three males with two females is unlikely to end well.