That is an interesting idea. It seems like, if such a medieval war was fought, it would have been many generations before the OT, so before the clone wars. There is also the matter of who would build such weapons. Vader implies that building a lightsaber is something that only Jedi can do, so I don't think it would be economically feasible to equip an entire army with them.

By the way, anyone else think that lightsaber should be be a term in this site's lexicon, so that it isn't underlined in red? Can that be changed?