Depends on the person I reckon. 10x should be plenty to get anyone to 500 (and well beyond, imho). Clarity of the optics and ability to gather light matter much more to me. The furthest shot I've taken on a live animal was 452 yds, at dusk, and I had my scope on 6x. Granted, that was a 280lb hog, which is much bigger then those described above...but he was jet black with a dark background. I would suppose ground hogs (never hunted them) would be more difficult to spot. However, Lit reticle and superb optics ftw.
It's interesting to me though, that most high quality binoculars come in 10x (ie: Leicas, Swaros, etc)
A NF, S&B, Zeiss at low power can dominate higher power, lesser optics.
I should note though, that aside of optics clarity and light gathering ability, I usually recommend the 2.5-10x mostly for AR platforms because of the size / weight mated with it's capability / functionality. If you are ok with a 50mm+ objective lens weighing you down...that works. They are just beasts on an AR though. I guess I think more of dual functionalities, and see the 10x limitation as being a very very limited issue on making hits at those ranges.
Works well on my bolt