Not that it matters but I would argue that this sort of organization is strictly required to operate at the scale of armies in question. The wars in the previo

Not that it matters but I would argue that this sort of organization is strictly required to operate at the scale of armies in question. The wars in the previous ages are described as being a bit more “equal” suggesting there were equally large hosts of humans/elves though, but maybe they’re able to organize “because magic” (e.g. elves may benefit from lembas bread allowing them to not have to worry about supply lines like the orcs).