Definitely see about finding a new place for some of those roosters to live, and give the hens a break. I try to have boys sold as soon as gender is apparent.
There is some science that the hen determines the gender, and some hens will consistently hatch more hens than others. BUT... to figure out which hens do that, you have to hatch a lot and keep strict records. If you're buying eggs to hatch, then the theory is no good unless the breeder sorts through them.
I usually get girls. This last time and the time before, I got 5 hens and 1 boy. I have only had one 50/50 split, the rest have been hen heavy. Never experienced more boys than girls, and my luck may run out at any time.
There is a rumor that temperature plays a role, but sadly that's with reptiles, not birds.
The previous hatch I had, all the eggs were from one hen, owned by a friend of mine. We wanted to know what a Cochin and Polish mix looked like. Super cute! Feathered feet and a half crest. But that hen yielded 5 girls and 1 boy, which gave some validation to what I had heard about some hens producing more males or females.
It is not cost effective to sort through hens to see what their rates are on a commercial scale, but it's something to play with in a hobby flock. Commercially, it evens out when you're hatching 100,000 eggs or more. To the hobbyist, it would be a fun project to see if it was true or not.