Yes, Luffy would be defeated.
Kenshiro would figure out how to get around the problem of his stretchiness and probably make his ability useless then strike him; I doubt though that he would kill him because he would give mercy saying that "that boy has a good heart" or something of the sort.
Raoh would force his chi into the points and destroy him from a distance, because Raoh would have no desire to fight somebody like him who is inevitably harmless; even if they did get up close Raoh would ultimately win just because of how he fights.
Toki would beat him but not kill him.
Jagi would brutalize him and if that failed he would go after his friends.
It's all because of how it's done, Luffy's powers are rendered useless in that kind of fight. Hokuto no Ken rivals DBZ and Bleach when it comes to fighters.