Yes
Yes. Roosters have many different vocal sounds. A reassuring clucking sound is common for roosters to make.
A term rooster is used for the male bird (the hen is a female bird) of certain species . There are chicken roosters and hens, pheasant roosters and hens, turkey roosters and hens etc. Ducks are drakes and hens. Geese are the "Goose and the Gander".
Well, hens are girls and roosters are boys...that cover it?
No. Hens will lay more when there is less stress put on them, and having roosters - especially too many per hen, too large of a rooster, aggressive roosters, etc - will cause the hens a lot of stress.
It is likely that the roosters are aggressive, too rough with the hens, or that there are not hens in ratio to the amount of roosters.
Hens
The amount of roosters needed for breeding hens is about one rooster per ten hens
Hens.
Yes they will.
No.
Better to say 4 roosters is too many for 4 roosters. The 6 hens can wait a bit and soon there will be one rooster a-go-go, one in the hereafter, one running away, and one squating on the ground. The hens could deal with 6 roosters, but the big boy a go-go won't stand for more than him with his flock. actually 1 rooster needs 5 hens to be satisfied other wise roosters will fight One rooster will service (fertilize the eggs of) up to 6 hens. If you have more than 6 hens, you will need another rooster. 4 roosters on 6 hens is not good. The roosters will fight and the hens will be exhausted running from all the roosters.