Prefaced with - This discusses some aspects of the story, spoilers ahead!
I've always had a soft spot for the Persian League. They reminded me of the Delian league, which is awesome, even if their support of the sector's most problematic power, the Diktat, for "down with the Heggies" reasons was always a little concerning.
However the story-line reveals that the League is just as broken as the Hegemony, without the nominal commitment to democracy. Particularly your interaction with a specific archon, and what happens afterwards (spoilers follow).
The story-line reveals a couple key things about the League that I at least was unaware of.
1) There is guaranteed freedom of movement between member planets, guaranteed by the League charter (good!) however I don't see how this can be even vaguely viable when you have outright dictatorships operating within the League who wouldn't be happy with their people up and leaving.
2) There is
significant tension between Kazeron and the other planets, and the League security forces seem free to act with a large amount of discretion, even if it impacts member planets domestically (a breach of the Leagues charter of non-intervention). This kind of tension happens (nothing is perfect) but then you find out that
Spoiler
the "troublesome" Archon is replaced with a member of an aristocratic family, presumably from Kazeron! Literally interfering with domestic politics of another polity for the personal gain of the ruling class of another polity, the new leader openly admits it!
For me this means that Hegemony description of the League as "an archipelago of petty dictatorships against coordinated mass action of the free peoples of the Sector!” is not that far off the mark. A point bolstered by their support of a literal military dictatorship.
In short, my perception is that supporting the League risks dooming the sector to an era of oligarchic rule and bush-fire wars between "independent" planets that are only such in name, so we're back at the Heggies being the least-worst faction in the sector, which is depressing because that's a
very low bar.