people are all different heights from 4' something to 6'+ so to me that is more real as not everyone is the same height,
Yes, we had that
it is basically about the different sculpting styles, mirrored in the body proportions, that can vary wildly; not so much about the actual size difference. Also, even if equipment can vary and was issued in different sizes, there is not that much variation in industrialized production. An army is different from a gang of Old West outlaws.
Anyway, here some comparison pics, first one a deliberate convolute,
from L to R - Artizan WW2, Renegade WW1 with headswap, Woodbine, Old Glory CIC, Crusader, Artizan renegade, Foundry
the second a hodgepodge actually designed to be a unit
as You can see, I am fine with even the ones that pop the large heads, Foundry, Renegade and the resin headswap in heroic 28 from Kromlech.
As to the resource sticky, given the interperiod nature of the collection, where do we put it? Interwar or Pulp?