As for Robin Hood... it's like Shakespeare. I prefer it to be as authentic as possible - as in period settings, costumes, speech, etc. I will admit to liking a few exceptions; I loved the Robin of Sherwood TV show and the musical West Side Story is a terrific adaptation of Romeo and Juliet.
IIRC, Shakespeare's historical plays were originally performed in contemporary clothes. So no togas in the 1599 production.
Of course the familiar legend of Robin Hood is something that was built over time. Elements like Friar Tuck and Maid Marian being added after the first stories appeared. Even the time period varies in some tellings. (Sorta like TOS
) King Arthur has similar "problems".