This kind of “political citation” happens even without intentional fraud.

When I was in grad school it was common knowledge that if you wanted to get papers accepted you needed to cite the people on the program committee and the likely reviewers - even if you didn’t think their work was particularly relevant to what you were doing.

Not as extreme as an explicit clique telling people they have to do it, but some of the distortions are similar - senior people are senior because they are widely cited, but you have to cite them because they are senior people.