I think most OP characters (except these damn princesses) are fairly unique. That being said, Whitebeard’s death scene gave me some really strong Zoro vibes. Despite not being a swordsman, Whitebeard was as proud and honourable as the best of them.
Mihawk and Zoro share superficial similarities such as being introverted and liking alcohol. However Zoro gets emotional much more easily and is clearly more literal and sensory than his master. While Mihawk is happy to laze around with a glass of wine and a newspaper, Zoro is all about training. You can see a clear change in Mihawk after Zoro lives with him, Mihawk finally gets off his arse and decides to fix his island after living there for 7 years and allowing debris to pile up everywhere. I can see where people are coming from when people say Zoro = X character but the differences are there if you look beyond the surface level.