Oh, we used to do this in a long running AD&D 2e game I was in. "No PC t-shirts" was one of the DM's sayings, and the party picked it up - we didn't accept others just because they were run by a PC.
I remember in one group, the Fellowship of the Azure Phoenix, I was trying to bring in a new character, and the remaining party decided to have auditions for a new cleric. I almost got upstaged by an NPC who they would have brought in.
And this was our "neutral, morally grey" campaign where the PCs intentionally took on the role of heroes because it got us the most perks. So my replacement character
was lying to them and they were right to be suspicious. I was a worshiper of Mask (Faerun god of shadows, thievery, and intrigue) pretending to worship Shaundakul (god of travel and exploration). Luckily by the time they found out they already realized he was supremely lazy (== efficient), and he convinced them that he'd rather work once a month and amass a fortune over a year rather than one heist against the party that would leave him looking over his shoulder for the rest of his life for a powerful
and vengeful party of adventurers. They bought it - sometimes the best deception is the god's honest truth. Depending on which god, of course.