You don’t need a transmission if you have hub motors. It’ll be sat on the garage floor, so it would be a great surprise if it was running.
I’m planning on doing something similar on my old hilux. The lack of power steering or power breaks or any auxiliary system that relies on the engine simplifies the build substantially.
While using the gasoline engine, the power accessories (power steering, power brake assist, ABS!) are functional, but when the gas engine is powered off, you'll have none of them? That's going to get someone killed. And on top of that, the climate control issues -- A/C won't work, and the heat will only last so long as the gas engine is preheated and then only briefly as the coolant isn't being circulated.
The concept of hybrid is an invisible marriage of gas/electric propulsion brought to us by Toyota who perfected it in the Prius. This is just a hack as far as I am concerned. I would be more impressed if the engine were removed entirely, and this motor were bolted up to the transmission as a replacement flywheel.