Every woman in Black Faction belongs to the Mistress. Everyone is expected & will die for her.
The protection units are an elite group of hand picked combat units repurposed to be the mistresses personal protection units.
At any one time there are over 90 MPU in the vicinity of the mistress, with an additional 100 chamber guards (all assigned to the Mistress now) and another sector (1000 Standards) near by.
There is alot of flesh to chew through before any enemy gets to engage with her chamber guards, let alone her MPU's.
MPU's are selected by performance and experience, normally units in their late 20s to early 40s, she wants battle hardened units surrounding her.
Once a Unit becomes an MPU its guaranteed that they will be expended in the role.
Aside from protecting the mistress they are used for the mistresses personal missions.
The mistress uses standards in support of her personal non company tasks also.
The MPU's find themselves in the most insane situations, incredibly dangerous missions and literal suicide missions.
MPU's take it on with Gusto, as they have undergone a rigorous re-education program essentially brainwashing them into worshipping the mistress like a god.
In fact the Mistress uses her MPU's in insane absurd missions, even false flags, like attacking her own bases where enemy activity is low to "boost the alertness of the units there" resulting in large numbers of expended units......