
And, shit, are these going to be human Jedis? Cause if Kit Fisto or whoever the fuck ends up in the Roman Empire...

Hrm. Maybe an alienoid from Star Wars might actually end up getting worshiped as a god. Aayla Secura would certainly be a sex god.
Yes I know these are Old Republic Jedi, but I don't know any Jedi assholes from the shitty NJO books, so blah.
You can kill Jedi by giving them clothes infested with bubonic plague fleas. You can poison their wine. Even if the Force can help them purge poisons, they can still be weakened enough or distracted for someone to shove a spear into their faces. You can catapult some jars of Greek Fire into the building their on. Catapult some rocks too! Hell, if a Jedi is on a boat, they can catapult some Greek Fire or some rocks on that boat and sink it. Do all Jedi know how to swim? Some can drown. Wasn't there a time where Romans catapulted snakes on to enemy ships? Catapult some snakes at the Jedi. Snakes and Greek Fire. On rocks.
If you do this far enough from shore, the Jedi'll be too far away to swim to land and so they'll drown. Unless the Jedi can use Force speed and, like, make themselves travel the waters like a ekranoplan.

Though if we use TPM, Obi-Wan and Qui Gon's swimming to the underwater Gungan city might make them out to be excellent swimmers.