old advice
One old saw was... "3" high at 100 will keep you on a deer with a dead on hold out to 300",... and the other was "on at 25 is good to 250". Least that was what I always read or heard. Old time shooter and hunter Jack O'CONNOR, among others, printed that sort of advice in their articles and books. This was with standard intensity 270 & '06 class cartridges.
Back in those OCONNOR days, scopes were smaller and line of sight was closer to line of bore. Rifles had 24" or better tubes for the most part and velocities were likely higher. I believe all that combined to yield slightly flatter point blank/overall trajectories than we see today with 22" barrels, 30mm scope tubes, and objective bells the size of the Palomar Telescope. This with standard intensity cartridges like the .270, '06, and so forth.
A lot of this zero business is dependent upon where and what you hunt, and I suppose, what kind of rifle you hunt with. Somebody in the laurel thickets of the east, or the pines and high cutover of the south, with their 180 gr loaded '06, may not need a 200 yd zero and be perfectly satisfied with "on" at 100. The muley or pronghorn hunter in the west, or the fella watching a R.O.W. or a bean field in the south with their big scopes and magnums, will want on at 200 almost for sure. Not everbody runs holdoff type scopes or is into, or has the time when game appears to click up and down for point of impact. A useful pointblank zero that allows quick holds and shots is still very useful.
My own experience with my rifles and set ups, and a few friends, indicates that a 25 yd zero will typically put a slug way to high at 100 to be precise with an "on" hold, and so high at mid range of 150-175 as to be near impractical. Similarly, 3" high at 100 is a bit better, but still puts the slug to high at mid range for me to really warm up to that zero either.
For me, zeroing a high intensity cartridge in the .270 class "on" at 100, is like running cheap gas or tires on your Corvette, you're robbing yourself of performance. I typically zero 2" high at 100.