About Law's crew, don't be hasty with the judgments. They're certainly not weak but don't let this chapter cloud your views on how they compare to the BB pirates. This is their first proper on-screen fight as crew, so of course, they wouldn't look bad right off the bat. But you have to remember that mfer Hawkins captured them all and took them hostages.
The last time Zoro stayed on the ship on guard duty, he met Kaku. CP-0's gonna have to use the same path that Zoro is in if they're gonna target Punk-1 first. At least one of them is meeting Zoro, and I doubt Oda's gonna let them be destroyed as soon as they entered the game. One of them might go after Luffy too IMO.