[@Dealdric]

not quite totally submissive. Mars is a duel empire, with own armies, fleets and and can do what what it wants and has independent military forces. Mars has a fair Independence for a adaptus. 

yes it it is reliant on larger impirum for resources but Mars has quite a large sway on impirum as a whole.  High fab has a perm seat on high lords. 

Old custodoes had right of life and death over anyone, not sure if thet carried on since inquistion founding.
They did however keep right to be part of emparors household and where only subject to his orders or that of there officers. 

Ie they where not subject to inquistion orders. a inquisitor cannot order a custodes. however cannot order someone like inquistion can legaly... maybe with some pointing of a Spear lol