Higher poly (where it counts), with adjusted weights to try and account for the increased distance between bones and mesh (e.g. at 50% speed: https://imgur.com/i6oolyw) which would otherwise result in weird pinching and deformation. Results are still not perfect, but... i tried. Use it if you want.
Disclaimer: at this size these WILL clip through the ground in various circumstances. Blame that on the animators... Disclaimer 2: i know female Au Ra tails 1-3 look bad when running, but as far as I can tell it's ONLY that animation, frustrating though it is, and my attempts to fix it by further tweaking the weights caused the opposite to be true. i'm sorry...