[Emyr]

So, if under the same throttle %, is it safe to say that the miles achieved by a 100hp moto would be the same as a 200 hp, if the 100 hp is not working out of it's normal working range?

The comparison isn't about throttle %.

For the same vehicle speeds, hence same motor output (assuming the smaller motor has ballast to bring it to the same weight as the larger to make the comparison easier), different motors will have different efficiencies according to their design and construction.