Who are the major factions in the sector and what are their rankings in terms of 'has their shit together'?
There's the
Riven-Gridley Octarchate, which is a large regional hegemon that happens to also have access to a mostly stable high-end pre-Collapse hyperintelligence. They're the most dominant power right now and have started throwing around their weight significantly more, in particular making claims on salvage rights that others find unreasonable and deploying military force to enforce those claims, although as a result they've caused increasing pushback amongst the other great powers. The border skirmishes and raids are getting significantly larger and better-organized, which means a bull market for mercenaries. Nevertheless, being underneath the Octarchate is hardly some dystopian hellscape so smaller powers often enough are willing to join with them - which often leads their neighboring rivals and foes to seek aid from another major party, which is driving the escalating conflicts. The Octarchate make use of various corporate military lineages in their combat technology - in fact, the "Octarchate" name is because they were a merger of surviving corporate branches and local offices from eight different Empire-era megacorporations. Octarchate government is a stakeholding democracy in two senses - first, your stake (i.e. your investment) into the polity gives you more of a voice, and second, your
stake (i.e. how much a decision affects you) also gives you more of a voice in the decisions that occur in the Octarchate. Because of the sheer number of votes which take place for the Octarchate, the vast majority of their citizens have proxies - duplicate electronic versions of their minds - which exist only to filter out and respond to polls and votes.
The
Polytechnica are an Elite-dominated meritocratic oligarchy which basically provides security guarantees in exchange for soul-pledges and resource tithes, which means that they have a cumbersome quasi-feudal organization - lots of small powers bound to them via treaties and cooperation agreements but self-sovereign and given of significant maneuvering room. They tend to be aesthetes and value individual excellence and expression, which makes their military forces somewhat less coordinated than they would be on paper - they're not plug-and-play because of extensive customization, which they handle by virtue of putting significant amounts of computing power and thinking into coordinating individuals and being individually capable. As the skirmishing between their vassal states and the Octarchate becomes larger in scope and scale, their relative advantage in small-unit engagements is rapidly diminishing, although their access to numerous Elites means that they're a very tough conventional force to crack.
The
Zerelian Holdfast are a largeish polity which had the mixed luck to be largely surrounded by a cloud of berserkers - which gave their predecessors in the Silence-era significant incentive to pool military and productive forces together to keep from being crushed under the tide of replicating weapons. Like almost all post-Collapse polities, they are heavily multiracial and multiethnic, but because of their origin within the sector and their cultural and religious ties the desert-dwelling reptilian kabilae make up a plurality of the population of the Holdfast. The Holdfast believe that a weapon you can't afford to lose is a weapon that you can't make good use of, so they tend to make use of a smorgasboard of whatever they can license-build with the immense amounts of salvage and industrial/computational power they possess. The Holdfast are actually a supranational union between a lot of smaller governments, with a government structured in a way which results in them having formal political movements (contrasted with, e.g., the Octarchate's different "moods" and the twists and turns of the Polytechnica's political nobility).
The
Penitence is a restructuring of surviving FORCE and THRONE assets who have been trying to restore sector order and government on the backs of Empire ideology, significant amounts of pre-Collapse caches, and their military might. The Penitence is a crusading order/battlegroup, organized along military lines although with significant lower-level officer autonomy, with various task forces having free rein to manage their day to day operations as they see fit. Unlike the Polytechnica, who seek worship and cultural subordination/assimilation, they care a lot less about what you do and more about how you do it, in Empire form. Penitent law works similarly to Empire conflict-arbitration, in which the permissible use of force is limited by the scope and scale of the issue people are fighting for and peace agreements are strongly enforced. Given the relative scarcity of resources in the post-Collapse, though, this means that a lot of Penitence-signatories end up using invariant technologies for conflicts, and non-invariant conflicts rarely see anything more than drone and commando assets being deployed.
There are also numerous second-tier and below powers, which don't have quite the necessary level of productive and logistical capacity or the technological sophistication to maintain more than a few
Elements, which are large AV task forces. However, they often have sufficient military might to make them too thorny to simply ignore, and thus can significantly influence how the Big Four behave given the right circumstances. Below these second- and third-tier powers are polities which lack the size or technological libraries necessary for sectoral relevance. Polities limited to synthesizing stable exotic matter (
S-tech) are generally ineffective against powers which can take full advantage of Architecture to dynamically change relevant physical metrics, and polities limited to technologies not reliant on programmable space and exotic matters (
I-tech, or
invariant technology) are even more out of luck, because things like antimatter bombs and fusion rockets are of extremely limited use against even drones or commandos.