I'm not personally expecting anything quite that linear from all the old opponents and acquaintances of the Straw hats, but who knows. Coby was never any uber fighter, though by general Marine standards he was certainly exceptional already, but the last we saw him, he was gaining the mantra style haki and was becoming quite the pacifist. I wouldn't be at all surprised if he had something else in mind for his future than hunting down and beating pirates, rebels, and other outlaws.

I'm not really sure what Smoker and Tashigi's role is in the bigger picture, but right now I'd judge somebody like Akainu far more dangerous. That bastard wouldd really enjoy watching Luffy die, after all, and would be quite a bit more capable of seeing it done than Smoker, no doubt. Smoker seems more like an obsessed small man chasing the coattail's of someone far greater. But perhaps we will learn something more of their role before this arc ends. I hope so. I know I'd enjoy a scene of Tashigi meeting Zoro again.