I think the only problem is that "are" should be "is". So...strager wrote:
I would only think there are more than one Cop if there are more than one Mafia. (Is that the right verb form? Guh, English, and other languages with weird conjugations.)
"I would only think there is more than one Cop if there is more than one Mafia." The reason is that you only have singular nouns thatt you're talking about in the sentence, so you can't use "are".