fact is in cannon (not counting earth 2 or golden superman) that supes is affected by ANYTHING alien.
luke = not of earth and alien, add to that force powers which is not science as non sensitive can not use in any way (call it what you want force lightning is space magic) and pure plasma swords (going off common lightsaber creation theory) which plasma reguarlly in comics is shown to burn supes skin luke has this fight in the bag.
truthfully though a sith lord takes it easier as luke is more pistol based and not into the whole kill/torture thing.
of importance is also that in red son lex luthor killed supermans super family with very little effort needed. (admitivly killing supes was hard to do and he only thought he did it) add to that that superman gains power only under yellow sun, becomes meh in darkness after prolonged battle, looses power in red and gains uber power under blue sun.
now lets looks at where starwars battles are commonly fought. aah thats right outerrim and between sectors in pure space with no light to hit superman. even common saber battles are on outposted stations/ships.