I've never really been on the "Armourer is up to something" bus, and I don't see that changing now. Gideon was visibly surprised to learn that those two Mando groups had joined forces, and it was done specifically at the behest of the Armourer. So she's obviously not a collaborator. Also remember that time when she beat a bunch of Gideon's men to death with a hammer? It's not like that was for show since she was the only one there.
That would be a betrayal of his character tantamount to desecration, given his religious beliefs.I would had his helmet come off before he died. Give the guy underneath some face credit.