I wouldn't say that games like Ars and Pendragon are Historical Accurate, more like Historical "Realism" in comparison to your standard D&D game. And in that regard, those games can be a great change of pace.
In both games, there was no "magic item shoppe" and "mayors" of towns didn't just offer up GOLD pieces to get you to clean out some "annoying" goblins. In those games, it's quite possible that said goblins could cast a few curses on you to boot. And in Pendragon, the magic was completely in the GMs hands, no healing spells or fireballs. (The rulebook was even judgemental about such concepts and called it "comic book" magic.)
The measure of a hero in both games was built more on the idea of how much he was willing to sacrifice, not how much he was willing to be paid (as in older editions of D&D.)