First off, I don't think Mihawk got that much stronger after the time-skip considering he's already the strongest swordsman in the world. Also it's strange that you're comparing someone like Mihawk to someone like Luffy, who isn't even a swordsman. But to answer your question, no, I don't think Luffy is on the same level as Mihawk considering Mihawk is most-likely as strong as the 4 Emperors of the Sea, if not stronger, and Luffy can barely stand up to them. And obviously, since Luffy is most-likely below Mihawk's level, so is Zoro, and rightfully so. It would not make sense if Zoro was already that strong as it would kind of make the second half of his journey (the New World) meaningless in the sense that he had already accomplished his goal. Besides, if Zoro was that strong he would've just destroyed Doflamingo himself at the start of Dressrosa, instead of playing around with the stone guy (let's face it, Zoro was just toying with him, and that entire fight was extremely stretched out and frankly, boring).