I don't think the numbers don't work in a completely linear way like that. Twice the capacity or number of cells usually doesn't always equal twice the runtime. And running at twice the output often means less than half the runtime. Just look at SureFire lights with LOLAs & HOLAs. But as mentioned before they are two different lights from two different companies. So taking measurements of the drive currents, Vf, even comparing the LEDs used in each light would give the best breakdown of why.
flash bang: You're probably thinking of the P1 or P1D. The E0 runs off of one AAA cell.