I mostly agree with RCDB’s logic on retracks; I don’t consider new Hulk to be a separate credit to old Hulk, and I don’t consider new Nemesis to be a separate credit to old Nemesis. I’m not even sure I’d consider something like CanCan Coaster to be a separate credit from Eurosat.
One notable exception, however, is that I personally disagree with them on things like Phantom’s Revenge and Powder Keg.
RCDB says that Phantom’s Revenge is the same credit as Steel Phantom and that Powder Keg is the same credit as Buzz Saw Falls, but I’d definitely consider those new credits myself, as the ride experience is totally different.
By that token, I’m tempted to err towards Top Thrill 2 being a new credit, as the hydraulic launch becoming a swing launch is a pretty significant change.