Rangers used to have a screening process in regards to the stewards they used . They seem to work very hard to make sure they are “Rangers minded.”
The kiosk staff is a bit of a free for all and they accept all comers.
Maybe I’m being disingenuous to them though and it’s the security firm they use for their stewards that seem to send predominantly Rangers fans to steward their games.
They did however, a few years back, as for match day volunteers from their support to do stewarding.