Dorward has basically cleared up your point for me, Luke2.
The Task Force is the main 'paramilitary' (for lack of a better term) which are subdivided within themselves, security units (police) and deployment units (military).
When I say 'scientific military organisation' I mean it is a military controlled by scientists rather than politicians, since these facilities started in the early 2000s privately by scientists researchers etc. they organised the entire New Commonwealth when the outbreak began, including the task force, who's sole duty is to fight the infected, save the survivors and protect the facilities.
Remember, this is a multi-national organisation, and each rank holds a specific position. Plus, there is only ever one vice to one full officer.
Captains have one Vice-Captain, Commanders have one Vice-Commander and Directors have one Vice-Director.
Cadet Officers are appointed within the cadet training teams.
Sub-Officers are awaiting Vice-Captains. This is a NATO OF-D rank. Each one may have a different role depending on the branch.
Captains command a Unit (between platoon and company size)
Commanders are in charge of a number of Units.
In this story so far, Commander Theodore Richard Blake is in command of all Alpha Units in the American-Canadian Facility located on the East Coast.
Senior Commanders command specific Task Force branches (security units, deployment units, pilot units etc)
Administrators over see the Task Force Units within each facility.
Directors are in charge of Task Force units within a sector or region, which may hold a number of facilities.
Senior Directors will be the main Commanders of a (surviving) nation's Task Force.
There will also be 3 Director-Generals as the overall commanders of the New Commonwealth Task Force (still unsure if there should be 1 or 3. I may stick with 3 to make it more of a council).
As for the NCOs:
Private (which I may change to operator) is the standard enlisted troop.
Cadet leaders are like cadet officers, they are appointed from within the recruit teams, and once training has been completed each cadet leader may be promoted immediately to either Team Leader or Section Leader.
Team Leaders are, exactly as they say, team leaders, fire team leader lets say, and deputies to the Section Leaders, who command a section.
Sergeants are a Captain's NCO aide in a Unit, like a platoon or company sergeant.
Senior Sergeants would be the NCO aide to a Commander (I might remove this rank though).
As for the Operational Assistants and Operational Advisers, these have versatile roles from quartermasters, technical experts, trainers, and advisers of Task Force members.
And as Doarward said, you have a separate civilian organisation, which is different to the Task Force.
While the Scientist, engineers and technicians are in charge (thus the technocratic society), there are a range of different departments within a New Commonwealth facility, including the Task Force, agriculture producers, medical professions, administrators, engineers/technicians, researchers, various scientific departments, etc.
Just to clarify, the Task force is only a deployment and protection detail, ensuring the safety of the people in the New Commonwealth facilities, outposts and some settlements as well as being deployed to fight the infected and search for survivors.
The Scientists are the main leaders, so to speak, over the New Commonwealth with a number of different departments to assist with the developing new society.
The Secretary-General will be the leader of the New Commonwealth, but mostly act as an arbitrator.
But anyway, this was just an idea, it isn't really the main focus, I was just bored