what is the tradeoff for 8x8 IFV vs tracked? Can the wheeled ones traverse muddy rasputitsa like terrain?
Wheeled vehicles are much worse at going cross country, but they can move much faster requiring much less maintenance when moving along good roads. Imagine a modern heavy truck travelling 500km along highway at highway speed, then idle a bit, then 500km back home, that's easily doable in a day.
If you want a bunch of tracked vehicle to do that you will need to load them onto flatbed trucks for the trip and offload at the other end, as per what Prigozhin did on his race to Moscow. Besides all that loading and offloading busy work these vehicles are vulnerable while being transported. On the other hand if you force tracked vehicle to drive on their track for this then after several hundred kilometers you will start to see vehicle breakdowns per we saw at the start of 2023 when Russian BTG where driving like mad in eastern Ukraine.