danny rand is the best martial artist in the marvel u.
because he knows k'un l'un martial arts. these are the secret styles. the masterful killing techniques. people like shang-chi know earthly martial arts, and cant defend his techniques.
iron fist knows how to defend all known martial arts. he is the living weapon.
so, if we're having a straight up martial arts fight with no powers, iron fist comes out on top.
and yes, moon knight and panther should be added. both badasses. but panther took a iron fist technique once when danny was possessed of some shit. got his ass kicked and suffered a brain injury that was supposed to kill him in the future. all from iron fist.