SFAIK, the only varmint hunters who really need near-perfect accuracy, and who shoot many rounds in one day, are the prairie dog hunters. As challenge, they try for hits at ranges well over 400 yards. In the larger PD towns, they might fire several hundred rounds in a day.
For other varmint hunting, many fewer shots are fired in any one day (or night). The density in terms of animals per square mile is just not that high.
The only time I ever got involved in many-shot, high-population density shooting was in northern Nevada some 20 years back. There was an incredible explosion in the jackrabbit population. A buddy and I parked his truck overlooking a few-acres area; we killed some 120 or so in just over an hour. We came back a week later; no evidence we'd reduced the population any.
(In Idaho farming areas at that time, the farmers built mile-long net-wire fences; a couple of hundred people would drive the rabbits into the vee and club them. Crop protection. Per a 1950-ish study from Texas A&M, seven jackrabbits eat as much grass as a cow. Sounds low; but, higher metabolic rate...)
FWIW, Art