The first post threw me initially, because in an EV conversion context "VCU" usually means "vehicle control unit", which is a processor (electronic control unit) that coordinates other components such as the motor controller with the rest of the car.
I agree that an entire electric drive system is an extreme alternative to a replacement viscous coupling unit (VCU), although if you want a hybrid that's one way to get it. Some production hybrids (most notably Toyota transverse-engine hybrids, such as the Highlander, RAV4, and now even optionally the Prius) drive the rear wheels only electrically... this would be similar, and it might even be possible to use a Toyota drive unit instead of adapting a motor to the Freelander's rear final drive unit.
Unfortunately, unless you add a generator to the drivetrain at the front as well, the only sources of energy for this rear drive would be what you store in the battery when it is charged while parked, and the little bit you recover in rear-only regenerative braking. The engine's alternator is not much for charging (and not highly efficient), and using it would require another DC-to-DC converter (for ~12 V to whatever you use for high voltage). You can charge when there is excess engine power available by running the rear motor as a generator while driving the vehicle with the engine, but this "through the road" charging is very inefficient.