It's a super hard to fight, by design, as you're outnumbered by level 5 enemies - and if you speak with them then there's no advantage of attacking out of stealth / surprise (so do a runner).
From a story prespective, you should have approached the Gith with *extreme* caution as they're fanatics and callus towards the "lesser races". At level 4 the fight is do-able with an optimised setup, and defeating them gives you a story item that continues the quest (outside EA), but generally the encounter is designed for Laz and her arc.
(Also if you're level 2 you can still stealth shoot them from the bridge for an easy win).
