You got me on the acronym.
The Army has a dedicated Special Forces command. Most of the background staff would be in place if you plug it in to an existing program. You would just need to look it up for vermillistude. Most Army Special Forces already use Fort Bragg in NC as their starting point. It's located near Fayateville,NC. If you need a base away from people, there should be a list of shut down bases that can be used. Also the base from Golden Age Champions could be used as a superhuman project. As far as numbers, it would probably be the same as a seal team.
I have no idea what would go as a package. Subject to orders and watched by command would probably be the best disads for this. WF small arms, some hand to hand, parachuting, survival skills, and a radio for coms might be good.
i suggest SHarper than a Serpent's Tooth for COIL adventures and background. It does a better job than I could.
There would probably be some kind of rivalry but the military executes mission based on its own intelligence and the intelligence shared by other agencies. PRIMUS is a civilian organization. There might be some kind of jurisdiction problems, but the Army typically answers to the Pentagon, while Primus answers to the department of justice. Different goals, different missions.
CES