State militias to help the regular military... What exactly makes your cult a state militia?

Useless question.  By definition all males of an age suitable for military service ARE AUTOMATICALLY MEMBERS OF THE MILITIA.

10 U.S. Code § 246 - Militia: composition and classes

(a)The militia of the United States consists of all able-bodied males at least 17 years of age and, except as provided in section 313 of title 32, under 45 years of age who are, or who have made a declaration of intention to become, citizens of the United States and of female citizens of the United States who are members of the National Guard.

(b)The classes of the militia are—

(1)the organized militia, which consists of the National Guard and the Naval Militia; and

(2)the unorganized militia, which consists of the members of the militia who are not members of the National Guard or the Naval Militia.

The Geneva Conventions recognizes THREE separate parts of a nations military forces.   First,  the REGULAR forces.   Those are the full time 24/7 military personnel.   Second,  RESERVE/GUARD forces.  They are part time soldiers,  the weekend warriors that get called up as needed.   Third,  and this is the one added after WW II due to the French,   LEVEE EN MASSE.   That is when the civilians take up arms to drive out an invader.    Such as the Free French in WW II.    To be considered part of that there are certain rules.  1.  They can only fight to drive out an invader,  they can not be sent outside the country.  2.  They must have a clear command and control structure AND be under the authority of the legally recognized government.   That means no RED DAWN type stuff,  you have to be under command of the recognized government and follow their orders.   3.  You have to obey ALL the other rules of the Geneva Conventions,  one being you have to wear a recognizable uniform.    So if my small militia group serves under the command of the sheriff it is legal.    I say sheriff because we have a long history of the local sheriff calling up a posse to go after law breakers.   It is the same idea,   civilians with guns are called up by a recognized authority to do something.   An example of this is the Northfield, MN raid by the James Gang.    Civilians with guns.   Or even more accurate,  the invasion of the USA by the Mexican bandit Pancho Vila when he attacked the town of Columbus in what is now New Mexico.   Besides running into the Guard,  he ran into civilians with guns.  

Many states have a state militia or state defense force that is similar to the National Guard, but unlike the NG, is completely under state control and usually unpaid.  Like the NG, they usually fall under the state's adjutant general.

Completely different than a bunch of rednecks getting together and calling themselves a 'militia.'

State militias are designed to be State-centered.

The US military may not be deployed inside the US.

the National Guard is the state millitia