Yes, and maybe not.
Example 1: Last year, around this time, I collected a huge batch of eggs so I could join in on a hatch-a-long here on BYC. After a week in the incubator, all 42 eggs (as many as my turner will hold) were clear.
Example 2: this year, that same HAL rolled around on BYC. I decided to try again, expecting the same result since both of the roosters in my breeding pens were molting (again). A week in the 'bator later, ever single egg was developing.
I don't know why last year was a bust. I had the same 2 roosters in the pens, and neither molt seemed worse then the other. Our weather was much better this year though, so maybe that was the deciding factor.
The general rule of thumb as far as rooster to hen ration is 1 roo:10/12 hens. But, in my opinion, those numbers can very greatly from breed to breed. I breed Silkies, and they do great in pairs, trios and quads. I have 1 roo: 8 hens in one of my coops and the other has 1 roo: 5 hens. I find if I give my boys a large harem, fertility drops dramatically. But, if you have a flock of active Leghorns or RIRs, it typically takes a lot more girls to keep those breeds happy. And sometimes a rooster will decide they have 1 or 2 favorites and they will only breed those hens. Roosters are weird (bless their hearts, I love them though)!
Just my $0.02 anyway