In fiction writing this pattern known as “Burly Detective” Syndrome, see https://www.sfwa.org/2009/06/18/turkey-city-lexicon-a-primer..., https://tvtropes.org/pmwiki/pmwiki.php/Main/BurlyDetectiveSy...
Thanks so much, I didn't know there was a term for that! And it was hilarious reading about the UK's use of "popular orange vegetable" to refer to "carrots", a great example of taking this technique to the extreme.
Fortunately, I don't think it's as bad to do that in fiction, because the author is going to establish how the world works to begin with, and therefore makes sure you have enough to know whether the alternate phrases mean that character or someone else, so, at worst, it's just cringey rather than confusing.
The Pope is an interesting example since they represent several things, each having separate responsibilites.
It just so happens that the pope has all those roles at same time time
Unfortunately, I consider that itself annoying because it then creates the problem of assuming your reader knows which of those are just alternate phrases vs other entities in the story!
Side note: this story got reposted twice recently so my comment on one of them (with examples of me producing a better explanation than the ones I had to wade through) got neglected: https://news.ycombinator.com/item?id=28241558
[1] Oops, another anti-pattern -- saying "this" or "that" when it's not clear what you mean. Here I should have said "this problem" -- it's a great technique for clarifying your own thoughts as well!