Bullet's came way before guns. It was just another word for pellets or rocks that you'd fling from a sling, based off the french word for "Little Rock", cause most bullets back than were little rocks. And besides that, the Dwemer already created steam power, and you've created smoke bombs. A bowless crossbow seems like a viable thing to attempt, powdered by explosives and and swinging it as a club is more effective in melee than trying to beat someone with a bow. Besides, if we're doing pirates, the old pistol and sword is a classic theme for pirates everywhere. Tamriel can only stay in a medieval stasis for so long. It's not like Hermaeus Mora kills everyone who tries to advance technology.