You may need more hens. Roosters mate a lot which can be hard on just a few hens. Definitely keep the more mellow of the two. I assume the broilers aren't staying long term?
If 2 hens set right near each other they often become confused at hatch time as they bond with their young through the egg those last few days. That why they chirp in the egg before hatch. Another broody may bond with them by sound, or hens will attack each other's young because they aren't...
How big is your coop? The smaller it is the more you will have problems. What exactly do you have totally? Number of birds, breeds? Ages?
Sounds like you need to do some separating. Meat birds should be by themselves. Any pesky cockerals need to be penned separately.
Broody hen should be...