Yes, that's Ed Harris in the Knightriders film poster!
I was saddened to hear that George Romero passed away a few days ago. I have fond memories of a time about fifteen years ago when we lived near a great video store (remember those?) that had prominent shelves dedicated to certain directors: Romero, Herzog, Altman, etc. While I love Romero's zombie films, Knightriders (1981) is actually my favorite of his. It's an ensemble drama (Altman-esque) about a troupe of knights who joust on motorcyles at Renaissance Festivals. It's got his signature social commentary. Starring a young Ed Harris (pictured above) in the King Arthur-type role and Tom Savini in the Mordred-type role. A must see.