I'm dumping the whole Starfinder Society.
The setting section of the core book states:
The Pact is not a single system-wide government, but rather an association of independent worlds bound by treaty to work together and acknowledge each other's sovereignty. Though its powers technically extend only to the facilitation of trade between worlds, interplanetary law enforcement, and mutual defense, over the last several centuries the government has gradually broadened the scope of its authority.
Borrowing" a few things from other games/media, here is what I've got as a multibranch replacement for the Starfinder Society.
mutual defense a.k.a. The StarForces
The StarForces are the military arm of the Pact and divides into a number of branches: Starship Command, Science, Engineering, Technicians, and Medical.
The Space Marine Corps is the elite assault force of the StarForces. Every Starship carries a complement of Marines for landing and boarding actions, as well as for major planetary raids and invasions.
The StarForce Commandos are an elite force within the Space Marines organization which trains for deep penetration raids and prolonged operations behind enemy lines. Commandos are also dropped onto enemy-occupied planets to assist BRINT agents to mobilize resistance groups.
Bureau of Intelligence - Military Agency
BRINT is the intelligence-gathering agency of the StarForce. BRINT operatives can expect to operate in enemy territory as ‘spies’ and saboteurs and may be required to organize and train resistance groups on planets Occupied by the enemy. BRINT agents also keep a close watch on the Bureau of State Security, whose agents are not part of the Military Establishment.
Interplanetary law enforcement:
Bureau of State Security BoSS
BOSS is a paramilitary organization which combines the duties of such services as MI5, the FBI, the KGB, and similar security institutions. The Bureau of State Security is a powerful arm of the Confederacy of allied worlds, for it is charged with conducting counter-espionage and anti-sabotage investigations, suppressing revolutionary and terrorist organizations, and maintaining the security of the state in general. Thus BOSS agents may be found in any government or civilian service, or in private business and industry. The Bureau is under the direct control of the Director-General of the Pact.
Interstellar Police Agency
The IPA is a paramilitary organization very similar to the StarForce and BRINT, except that it is charged with maintaining law and order in the volume of space controlled by the Pat and concerns itself with criminal activities of an interplanetary and interstellar nature.
Trade between worlds:
Merchant Marines
The Merchant Service is organized on a tight Guild structure. Normally, employment is maintained in one of the Guilds, but a general SpaceHand position may be obtained by any personnel unable to obtain employment in their Guild position. Most large vessels are owned by large corporations as both the cost of the vessels and the cost of operations are far too high for many private citizens to manage.
Department of Interstellar Survey
The Department of Interstellar Survey is charged with the exploration of deep space, to discover and chart new planets suitable for colonization, resource exploitation, etc.
Survey Scouts
The need for new Colony and resource planets is never satisfied, and while the Survey Service does extensive work in the discovery of new planets for settlement and industrial development, independent exploration companies have also entered the field. According to Interstellar Law, the discoverer of a planet uninhabited by sentient races becomes a First Claimant to all land and resources on the planet. If the discoverer undertakes the development of the planet, a very costly enterprise until returns are won from that development, he literally owns the planet. In most cases, the Only organizations capable of such development are governments and the great interstellar corporations. However, a discoverer can also sell his interest in his First Claim, the value of the Claim being dependent on the potential of the planet for colonization or resource development and the difficulties that may be encountered in undertaking such development.
Mercenary Companies:
The Mercenaries are fighting men who have, for the most part, been released from the regular forces. Mercenaries hire Out their services to the large interstellar corporations, to frontier planets that lack sufficient population to maintain a regular planetary defense force and need professional ‘stiffening’ for their Citizen militias, and to independent merchants requiring a heavy guard for voyages into pirate and enemy infested space.
