I'm writing a Reasonable Brotherhood of Steel.
Powered armour is rare, and only used for the worst situations. Brotherhood Knights need a proper helm, modified for ballistic protection, of course.
*Grotesque helms will have the ceramic overplates shaped into animals or whatnot.
This works well, as both basically have a glacys that can be reinforced to resist firearms.
And the Grotesque coming in third would be great for knights feeling more audacious.