Yeah, I'm kind of convinced that Zoro and Sanji are capable of using CoA, as well. I just think it's fitting for the monster trio to all be capable of thrashing Logias now without (always) relying on some goofy gimmicks.
That being said, even if Smoker is now capable of using haki + rokushiki, I doubt that would spell too much trouble for any of the trio, especially since they were all capable of conquering the latter before the skip, anyway (lol seriously, what use will tekkai + logia intangibility be against Luffy?
).