I believe this is how it should be
Legion standards - FX, TE, AP, etc. (Pretty much any helmet)
Mark Deployment is a helmet such as TE, GF, Gino, AP, ANH2.
That is the whole point of being Mark Deployed. You are going for the look of the movie style trooper.
So FX helmets are fine for the Legion but for Mark Deployment in the FISD it should not be.
I think that is the idea behind Mark status.