While Zoro will definely not rule over all swordmen, because first, its impossible to do that, second why the hell would Zoro even want to do that? Being the strongest swordman alive dosent mean you rule all others...Dosent mean you rule any of them at all, just that you are the strongest. Even Luffy dosent want to be king of the pirates to rule over anybody, in fact he loathes the idea of having to rule over others as it was shown when the grandfleet was formed, he dosent want the responsability of dealing with followers.
Now adressing your comment.....
Why and most importantly HOW the fuck would momo rule over all swordmen? Wano only has a small fraction of all swordmen in the world. Remenber all samurai are swordmen, but only a minority of swordmen are samurai.