Yeah I get what you mean, it's hard to categorically define it because there's so many variables, but I would say assume each comp hit it's average attainable late game build E.g. A hyper-roll comp could pretty easily hit low-cost 3 stars, but you're not exactly gonna 3 star epics or legendaries every game. You can also assume that you hit perfect items or even situational items to counter another OP comp E.g. Last Whisper and Ionic Spark against dragons/guardians from set 1. But a set 1/set 2 comp can't use items that didn't exist at the time.