I have not thought about this factor.I think you gotta factor in the fact that they (should, at least) deplete the hunting locations and thus should see lower gains over time.
I have 2 hunters I switch between hunting and scavenging as necessary.
But the 10 days run have been made at day 35, and both have been hunting non stop since day 2, so I believe that the numbers I get are sustainable. May be if you have a greater number of hunters would be something to tiink about.