There's a merchant in the Starfarer's Refuge who sells Vanguard weapon crafting recipes. Why does he sell that stuff when the Avikan already have those recipes unlocked and he gives a quest that unlocks all recipes relating to that race plus the Droden? He seems useless as a merchant NPC, honestly.

Meanwhile, there's a NPC much like him in the Creon Embassy but this other merchant actually sells weapons instead of crafting recipes for weapons. Feel like he's supposed to be like that but isn't for some reason.