A fundamental principle is total absence of science as argument to support eating anything for any reason, or as means to choose proper foods. So, no clue about calories, vitamins, minerals, fiber, essential fatty acids, protein and amino acids, and basically anything else measurable through direct analysis. So if we want to find out what they ate and why they ate it, we can't use any method they didn't use.
For example, the adrenals to cure scurvy or other ailments. We do a direct analysis of adrenals, and find all kinds of therapeutic things in there. We conclude, that's why they chose to eat adrenals. No, cuz they never did any kind of direct analysis. The reason they chose to eat adrenals is empirical, through trial and error, they ate it, looked at the effects, drew conclusions.
Or for example, lichen and other plant stuff pre-digested in caribou stomach. Lichen and other plant stuff is toxic to humans as is (as written in the article, I don't actually know, but that's the premise), but not if it's pre-digested by a caribou, right? We must know this from direct analysis of lichen, but also from actual empirical knowledge of eating lichen. Well, they have that same empirical knowledge about eating lichen, cuz that's the kind of knowledge they have, the only kind of knowledge they have. Which one would they have known about first, the effect of eating pre-digested lichen in the stomach of the caribou they just killed, or the effect of eating lichen straight from the ground? Well, when you're starving, and when you're smart, you look at what other things eat. So, they knew the caribou ate lichen, so they must have tried to eat it too, cuz food is food, why not try it, we're starving and dying anyway. They try it, get sick, die, don't try it again. Oh, got an idea, if lichen is good for the caribou, but it makes us sick, maybe the caribou can somehow neutralize the stuff that makes us sick so it doesn't make it sick. Maybe it's in the stomach cuz stuff gets transformed in there, and we know this from empirical knowledge. OK, let's go kill a caribou and see what gives. Right, so here's a freshly killed caribou, we're all starving so let's try to eat the stomach with all that pre-digested lichen. Hey smart guy, we just killed a caribou, it's got 100lbs of back fat on it, and you want to try to eat the stomach full of toxic lichen?