It's nice too see someone thinking outside the box like this!!! Almost all RC tanks will favor one side or the other... even real tanks need to be slightly corrected some. I've seen RC cars and trucks do this too, unless you're taking you tank for a walk? Just make sure you know which way to turn the end bell. LOL! You gotta be a pretty experienced to go this way. IMHO.
Just don't compromise the wiring inside.
I once raced HO slot cars and unless you ran in an unlimited armature class, twisting the comm was forbidden. This is why soldered tabs were not allowed as crimped tabs on the comm were difficult to alter and can be seen through a set of loops. AND, it was for a marginal gain too, depending on the track requirements because it didn't make more HP, just affected available torque.
If it bothered me that much I would entertain using a different motor rated at another RPM on that side.
Jeff