So there is basically an Ash or a Bishop in each team?
The official breakdown, in both the Aliens Tech Manual and in the ALIEN RPG Colonial Marines...
The 4 standard types of team:
Rifle Team: Rifleman, Corpsman (rifleman & medic)
Gun Team: Smartgunner, Combat Technician (rifleman/armorer)
Tactical Team: officer (Commissioned or warrant) or Section NCO (Sgt), driver and/or gunner, and the APC
Support Team: Dropship with Pilot and Crewchief.
Marine Squad: 1 rifle team, 1 gun team, including a corporal and a lance corporal as team leaders, with the corporal also the squad leader
Section: 2 squads, a tactical team, and a support team.
Platoon: 2 sections, one with the Platoon Officer (usually LT), and the other with the platoon SSgt.
Company 2+ platoons, with a captain and a gunny in an additional tactical team, and a support team for them. Plus at least a couple additional enlisted and warrant admin who don't deploy.
It's a very sparse organization.
There are also specialty teams which can be added or substituted into platoons.
Recon: Forward Observer and Marksman (=Sniper)
Assault: Breacher with RPG, Combat Technician
CBRN (Chem, Bio, Radiological, Nuclear): CBRN Defense specialist, combat technician.
The Synthetic is a platoon level asset and a non-combattant warrant officer. (Ripley is commissioned as a warrant officer to be allowed on the mission in ALIENS. She's doubling Bishop's spot as tactical advisor.)
ALIENS is pretty unique amongst action sci fi flicks by having developed a TOE
before shooting....
Not a great one, but at least they had one, and made it available to the secondary publications authors.