Capellan Confederation Snipers
Free Worlds League Branth Infantry is technically seven people, but demands seven tons because it's also seven dragons.
The two manei domini teams of course
The Ebon Keshik unit
MOC Ebon Magistrate unit
The field medics already mentioned
Deep Periphery assassin team
That's the whole list of single squad units in TRO 3085/3085 supplemental. If one is looking for pathfinders of a non-specific variety, my suggestion would be to use the capellan confederation snipers or deep periphery assassins and ignore their affiliations.