I was thinking more of optimizing for weight. Also, if you optimize for narrow RPM, then you are only using the gas engine to power a generator, so you have so

I was thinking more of optimizing for weight. Also, if you optimize for narrow RPM, then you are only using the gas engine to power a generator, so you have some loss there. I'd rather have the gas engine power i.e., the front wheels, while the EV powers the rear wheels (or vice versa).