@Blaser @lonespace is exactly correct about not putting too much stock into what you’re looking into. Tinkering is fun but those numbers wont help you. Real world numbers never worked from the beginning. What plane maker and datarefs read may differ from animations. Trust your instruments, the animated ones. Even those are tweaked since it’s nearly impossible to get 100% right.
As far as the “prop engine” specs you’re peaking at in plane maker… The horsepower is exactly double, yes. Think of it as one engine and prop pointing upward. I know there are two engines in the helicopters but this is not how “plane” maker works. If there were two “engines” then there would be two “props”. So the horsepower is combined into the one “prop”.
Don’t over think it.
Have fun guys!
Hope that helps and thanks,