Agree that detached clover on it's own is not sufficient, there are definitely other dies which exhibit that. The clover is just a useful additional thing to check to give extra confidence after first looking for the obverse flaw and 4 colon positions on reverse. Those are usually the easiest things to see anyway.
As you say Richard, the die flaw is the unique definitive identifier.
Just one other thought, on the 8/? (similar die to 8/6), I have noticed that all 3 examples I have owned have the flaw clearly exiting bottom left of the C of VICTORIA. This is probably easier to see than whether the flaw starts between teeth or centre of a tooth, so should help members to identify the obverse die.....assuming it's always present!?
Picture below illustrates