I get the idea that thicker means less slip. But what conditions would make Eddie want to put thick front thin rear versus Harry the opposite? Is it different conditions? Different personal preferences? Or different vehicles? The MXB-3 (where Eddie commented) and the RXT (Harry's) are both 4WD 3 Diff. So why opposite diff oil setups front versus rear?

Sorry for my lack of experience, but I would really like to understand how to use the diff oils to improve handling.