I think you can leave the Arquebusiers in the game.
I guess if we were going to move up to the 16th century, they would be ok.

Chinese handguns entered Japan in 1510. But the Arquebus had to wait for a Portuguese shipwreck in 1543. Six years later, the Tanegashima matchlock (reproduced Arquebus), was in first used in battle, remaining virtually unchanged until the 1860s.

As far as I can find, “any” muskets must have been imported from Europe (Spain) in the later half of the century, but the Japanese were not manufacturing them. So I doubt that there would have been many of them in comparison to their own guns.