Samurai, gunslingers, and pirates are even more reasonable. There was an age of piracy located in the Caribbean and gulf of Mexico a few decades before the wild west. They’re unlikely to be fighting at the time, but as New Orleans settles down it’s plausible that a pirate may want to open a saloon or brothel outside the reach of the government and polite society. During the wild west the Japanese government underwent the Meiji Restoration which ended the feudal system and put a lot of samurai out of work (they had a rebellion about it). A samurai deciding to hop a ship to America to seek ronin work is something I feel like i would’ve heard if it had happened, but it is within the realm of “yeah I wouldn’t question if a mostly reputable source said it happened”. And well I suppose one or two western style gunslingers may have been in the West at the time.