Eh. Like 90%+ of everybody who ever lived in pre-Industrial civilization was a slave or a serf or something like that. What does that say about the other 1% that “owned” them? And if your goal is explicitly to bring lots of revolutionary technologies, you’re probably going to disrupt a lot of established power structures. People in power don’t tend to take kindly to that, and as the ultimate outsider, you’ll be the perfect scapegoat for anything that goes wrong.

It’s dumb to think only about fighting, and this specific scenario isn’t something that you’re ever going to be able to win through brute force alone. Also, using guns “to make them listen to you”, as the original comment said, sounds pretty evil depending on how it’s done. (E.G. Menace and threaten anyone questioning you: Evil. Gain favour with the royal army by providing guns, then ask for funding for medical research: Less evil.) But ultimately, it’s reasonable to be prepared for other people to act in bad faith.