[JesseK]

Hmm, interesting points above made me think of something.... Arguably, you could take 1 FP + 1 Banebots 545 through their own AM Planetaries into a toughbox and have that drive one side, with an identical setup on the other side. Estimations for worst-case here are that each motor pulls 5 amps when you're pushing. This is only doable because of the coefficient of friction though. So long as the chains drive all wheels that touch the ground, it would work ok. I'd argue that acceleration with this setup is very close to that of 1 CIM per side.

It's downside is that it adds much more complexity than needed and is somewhat expensive for what you get.