[asid61]

I think the reason a 6 cim drive gives you more acceleration is because it spikes the current initially. I'm not 100% sure why it is faster at accelerating (it definitely is though, one of parents did some calculations) but that would be my guess.
It won't help in a pushing match because the current spike will just kill you, because the current will not decrease over time like when you start driving. Insert blown breaker here.
The reason I say torque is limited is because torque is directly related to current on a motor. Because we have (usually) a maximum 120a-180a going to all cims, and the stall current on each cim is 133a, you are not getting more torque. The delayed blow on the breaker will allow the current to spike for all the cims, giving you a torque boost with more cims, but it can't hold those current levels for long. So the max torque cap is pretty much the same if you don't want to blow breakers.

Torque is also inversely proportional to speed in electric motors, so having 6 cims divvy up a given amount of current (torque) will increase their speed as well compared to 4 cims.

Let me rephrase what I said about manipulators:
6-cim drivetrains are fine. You are still left with many motors for doing all kinds of stuff on the robot. However, when you have a bunch of turning motors too (which you will want, crab or swerve) then you end up being left with some wimpier motors. On a single centralized turning gearbox, it might not be a problem, but if you want to turn the modules quickly then you would want more than 1 turning motor there.

Just my opinion of course. 6 cim swerves have been done in the past, and have done beautifully. However, in my opinion, it doesn't matter what you pick as long as it's excecuted well and you get driver practice. Focus more on the little picture.