There is a variation where the motor drives a dropdown over each truck, eliminating the U joint problem with the shaft coming out of the fuel tank. Old as the hills, and in all All Nation Diesel models.
The China drives could be made in the same gear ratios, and then would have roughly the same speeds and pulling power. The problem is that the motor bearings absorb radial force due to worm engagement, and those spur gears can get rocks in them. Those two problems are not a real headache unless you run eight hours a day for years or have loose ballast.
