Calling up the unorganized militia has at least these benefits:
a larger force at a lower cost to the state
coordinated action - more effective & greater safety (friendly fire)
indemnification
The militia could probably benefit from organizing itself with chapters and a central head with a screening process that deflects felons and individuals with a propensity towards unstability and a substantal number episodes of violence. A certification training for firearms proficiency and educational programs for defense strategies and military tactics wouldn’t hurt either.