I'm not sure I totally agree with the premise, but I think the issue here is related to the value we give to that first letter in the acronym.
Role in videogames is usually intended as its function in the game environment, how the character uses his/her skills in the battlefield, but is basically all about battle anyway.
Role in tabletop games is something deeper, may vary entirely the playstyle of a given character.
When designers come up with a tabletop character concept most of the times they start from lore and "feel" and develop game stats from there, not the other way around.
Or at least that's what I hope it's like, I actually think that would be the healthier approach.