We have still to see how strong Who is who actually is and btw if he beats him without many problems we are still at square one. Still it is good for Sanji to get the left hand, if they now start to fight for real, since it could mean that the old M3 ranks still stand. Hoping, from Sanji point of view, Jinbe doesn't pull a Zoro and does something like tank a combo attack from Kaido and BM (that would of course put him above any yonko commander fight he can get). Worst case scenario, actually a real big troll move from Oda (but I don't see Oda actually doing it) would be to make suddenly Jinbe fight King.