Burgess has been referred to as Blackbeard's right hand man, and commands his 1st Ship. Shiryu commands the 2nd Ship. So, obviously, they're going to fight Luffy's two Wings.
Burgess and Shiryu are fighting Zoro and Sanji in some way, the only question is who is fighting who. If that's the case, then Burgess needs to be on Shiryu's level, since Sanji and Zoro are pretty evenly matched (overall, right now Zoro's a bit stronger).
Burgess and Shiryu are fighting Zoro and Sanji in some way, the only question is who is fighting who. If that's the case, then Burgess needs to be on Shiryu's level, since Sanji and Zoro are pretty evenly matched (overall, right now Zoro's a bit stronger).