Co-Head of the United Standings Improvement Agency [USIA] here. Among other things, we permanently unlock epic arcs for our clients and provide them guidance on how to run them.
Every epic arc is soloable and intended to run solo without blingy ships or max skill levels. The arcs are not “L5”, they just require 5.0 standing (which isn’t that high - it’s the same standing required to unlock L4 missions, and arc difficulty is comparable to L4 missions). The pirate arcs require only 3.0 standing and are substantially easier than the empire arcs and require substantially cheaper/lower skill fits and are much faster to complete.
So you have the SOE arc + four empire arcs (two which are shared with Sansha/Syndicate in terms of paths/rewards), and two pirate arcs for a total of seven soloable arcs.
If you have any more questions on how to unlock and run the arcs (advice is free) or would like us to unlock the arcs for you, head on over to the USIA Discord server and we’d be more than happy to discuss the matter further.