Timing is pretty critical. As was said lots of areas resources are limited lots of the year. Every doe might be getting breed, but it might be fawning window of over 3 months.
I have some areas with terrible buck/doe ratios, however you wanna call it, high low, but in that 1 buck to 8 does, maybe worse. I'm getting Fawns from start of May into August, so likely some does are hitting 4 estrous cycles. Those late born fawns are always going to be behind, if they even make it. And we are that limited on resources.
I remember reading a number of years ago the record was a buck only breeding 8 does, I don't know how much they can track that, maybe it was in captivity, or that was in the wild and it's a limited amount they can document, hard to say. But pretty unimpressive if you compare to domestic animals.
Key and point being I think, you want all does breed in a relatively short window, none of them going through more than 2 estrous cycles, most hopefully only 1, atleast for best fawn success.