[Ether]

Originally Posted by WizenedEE

you should be able to get the same amount of force in any direction

Not so.

In the "forward" direction (as specified by the OP), the maximum vehicle force is

Fvehicle_forward = 2*Fwheel*COS(30) = Fwheel*sqrt(3)

... whereas the maximum vehicle force in the sideways direction is

Fvehicle_sideways= Fwheel + 2*Fwheel*COS(60) = Fwheel*2

where Fwheel is the maximum available drive torque on the wheel times the wheel radius, or the maximum available wheel traction, whichever is less.