They look like this:

And they shouldn't. I assumed it was because I was missing AnimationLowRes, but when I added it the units just floated a little bit off the ground and the problem still persisted. I also tried using SkeletonName and SkeletonLowRes, but they both created the same problem of using AnimationLowRes. I'm pretty sure I've seen this solved somewhere before, but I can't seem to find where.

Is the LowRes geometry actually a low-resolution geometry? I've had this problem as well and I think it's because the low-res human skeleton has fewer bones than the high-res one, so if you're using the high-res geometry on a low-res skeleton you're going to have points that are missing their deformer bone and behave strangely. I think they stretch down to GroundDummy or DummyRoot?

Disclaimer: I'm not 100% sure about the above-mentioned theory. But I'm 90% sure.

Ahh, yes that was the problem. I wasn't actually using a lowres model for the lowres setting. Now I just need to make lowres animations. Thanks!