Throughout the series, Oda has stressed the similarities between Luffy and Roger by paralleling them on numerous occassions. While not to the same degree, I think it’s pretty apparent that Oda is paralleling Zoro and Rayleigh in a similar but more subtle manner.
They both possess scars on their eyes. The scars are obviously not identical but they are both an important part of their respective appearances.
They are both drinkers. Not much to say here, drinking is a huge part of Zoro’s character and on the other side, Rayleigh has been shown to drink on several occasions with his flask or at Shakky’s bar.
The signature sitting pose. This is nothing major but I thought it interesting that when Rayleigh first met Roger, he was sitting in the same position as Zoro often does. I can’t think of another character off the top of my head who sits like these two.
They are both swordsman.
Neither of them has a devil fruit.
They are both Vice-captains/first-mates of the late and future pirate king respectively. Both, Rayleigh and Zoro were the first crew mates of Roger and Luffy respectively. With Rayleigh being formally named the VC to the pirate king. On the other hand, Zoro has not been given any actual title. However, many others in the world (or at least Bartolomeo) consider Zoro to be the unofficial Vice-Captain of the strawhats. There’s also the fact that Zoro is the only other member who was considered a Supernova.
They are /will become legends in their own right. Of course, being members of the pirate king’s crew automatically puts all the crewmates in the history books, but Zoro will become a legend like Rayleigh by his own merits. It’s clear that Rayleigh is highly regarded in the OPUniverse but to push home this fact, we should remember that Monkey D. Garp himself said that the marines should not attempt to confront two legends at the same time (referring to Whitebeard and Rayleigh). Zoro eventually surpassing Mihawk will obviously put him on legendary status as well. Considering the current World Strongest Swordsman was referred to as one of the legends among men by Oda himself (he mentioned Mihawk, Shanks, and WB as being “legends among men” specifically).