I haven't looked at any spreadsheets and I don't really know how top players perform, but I have to say that I've barely seen 2 or 3 BLUs actually deal real damage, the rest were lower than any other DD who actually worked on their gear, obviously sparks DD doesn't work. You never see a BLU for example WSing for 70k damage, or making huge Skillchains, yea they spam that CdC button, but that CdC is not so big damage. Obviously a BLU with Almace can do great amounts of damage, but in the same way another DD with empy weapons or mythic weapons can do good amounts of damage.

But IMO BLUs are usually chosen not because of their damage, which is commonly low, but because of their survivality. My Dancer for example is usually dead after the first or second WS in high level content like Omen because tanks have no way to get hate back.