@Die$el
Alright, in the nerdiest way possible, I'll explain the factions at large.
The Free Galactic Alliance [FGA] is sort of run like a mix of the Klingons/Romulans from Star Trek with a dash of the Empire from Star Wars.
This quote fits the FGA really well:
"In keeping with their xenophobic and arguably racist attitudes, the Romulans [But in this case, FGA races] tend to conquer species rather than form alliances with them, and individual [...]s tend to treat other species with varying degrees of disdain."
The New Galactic Republic [NGR] is run like the Federation from Star Trek with some elements from Dune's Imperium system. IE: The use of dedicated guilds for certain occupations, the divvying of territories and fiefdoms based on the contribution as well as favoritism, etc.
The Galactic Trading Guild [GTG] is one of the established guilds under the NGR's decision to create guilds - but it is so large and so independent, it's easily considered a separate entity from both NGR and FGA and exists in a sort of pseudo-neutral status.