The most important part for getting someone into fighting games is to make sure they have fun. And part of having fun is being able to play a character that one enjoys, no matter how good or bad it is.
True, but at the same time, once you start whatever multiplayer you choose, even if fairly casual, it's super-annoying if you basically can't play your fav since it's one huge handicap. I suppose for a complete beginner it wouldn't matter too much, but I doubt that'd last long.
But it's basically the same for all games. Certain strategies, weapons etc are the most effective, and then you either do what everybody else does, or accept that you are going to lose against players of equal skill.