A long time ago...far...far away, I used to drive a little M114A1E1. (Recon platoon, 2/81 Armor, 1st Armored Div) It was a fully tracked, armored vehicle. The only time I ever bogged/imobilized this vehicle is when I broke through some ice into a pond. Burried up to my lights. But otherwise through mud, snow, etc. I never bogged down. In fact, during four years, I can not remember seeing anybody else tank, pc, or scout vehicle bogged down. Broken down because of engine or track failure yes, bogging down no.
Just my 2 cents.
Magic Cat