Can't speak to Mulan - never seen it. But Luke and Han operate within a galaxy of other individuals who also adventure and have powers and are the protagonists in their own stories. That it's the Luke-Han story being told doesn't invalidate all the others, nor does it mean Luke and Han can operate in ways all those other protagonists cannot: they have to fit within their setting just like everyone else.
Not intended as insulting, just trying to point out that if the PCs really are the only adventurers in the entire setting there's nothing stopping a DM or a rule-set from making them be absolutely anything without regard to the rest of the setting. It's exactly the same as if the PCs are aliens within the setting - they don't need to conform to it.
Luke started off as a nobody living in a relative's basement with no badass force powers, rot ripped off by jawas, almost died to a tuscan & had to be rescued by obiwon where he learned a bit about his dad & discovered the need to go off on a quest because he lacked the ability to do much of anything & even after meeting yoda it took him quite a bit to rise to the point where he could make his father's lightsaber wiggle. It sounds like you started star wars like 6+ movies in & think luke was always a badass because the first time you saw him was a cameo of an old PC in a new campaign with different characters?