For the organization of the security divisions in 1941, see:
Sicherungs-Division
As you can see, it had a reinforced infantry regiment for anti-partisan missions.
The
Landesschützen (militia) and
Wach (military police guards) units were for guarding installations and protecting communications. The Military Police had various area administration headquarters, as well as POW transit camps.
In addition, there was a secret police directorate (admin headquarters) with several secret police units.
There was also an armed Police battalion, (i.e., civilian police, not MP's), concerned with "normal" civilian police duties. [Normal,because besides their standard law enforcement duties, the Police units were also heavily involved in "Holocast Activites", and murdered thousands of civilains.]
Last, but not least, the divisons had somewhat reduced service elements.
Cheers
Leo