No, I think that would be even less efficient than a bike with one motor. If that was a more efficient option, you'd see more commercial e-bikes with that kind of setup. The most efficient e-bike is one with a lithium battery and is as lightweight as possible. The reason why I think gasoline is better on hills than e-bikes is because of how energy dense gasoline is. You can store all this energy in several gallons of gasoline. It's only been since the invention of lithium that electric bikes can now compete cost-wise with gasoline powered scooters. That's why you weren't seeing a lot of electric bikes before. It was because lead acid powered e-bikes, over the long run, were more expensive to get you around than just running a gas powered scooter. Now that we have batteries that last 3000 cycles or more and potentially 7 yrs or more, e-bikes are competing with gas scooters.