Yes, as you can see from the picture above, that prototype design, while being liberal with spacing, could still fit perfectly into 22 holes.
If you cut down on any unnecessary spacing, then this kind of differential with any associated gears could fit in 20 holes width and, depending on the choice of the wheels, entire chassis could be as narrow as 25-27 holes.
This kind of the differential transmission could have friction losses equivalent to the regular drivetrain design, where all 4 motors are located on the back of the chassis, with 2 directly powering back wheels, and other 2 connected by the chain to the front wheels.
The main trick to the low friction is that axles coming out of the motors do not support 60T gears that motors are attached to. Instead, 60T gears with motor assemblies are supported by the drilled out 393 output gears and, when everything is aligned correctly, motor output axles are passing through without even touching them.