Look up the strength differences in the great apes compared to humans. You will see we are the ones that are dreadfully weak. If the gith have anything akin the the muscle fibers of our earth bound cousins…. Humans build bulk to make up for our genetic weaknesses.
Yeah, once you look into inter-species comparisons, you can't really simply use mass to extrapolate "strength".
Even when comparing humans to monkeys (which much closer genetically when comparing humans to giths), the latter are documented to be much "stronger" than humans because their muscle mass consists of much more fast-twitch muscles. Whereas Humans "specced" heavily into endurance with much more slow twitch muscles.
Historically, the leading theories are that humans have relied on extreme endurance and superior heat dispersion to run down and outlast animals as a part of our hunting strategy. So we're not exactly built for explosive strength. And obviously none of these historical factors even matter in FR setting since the existence of magic probably completely overhauls human evolution. How important is a hunter gatherer society when gods exist and let you cast create food and water?
