However, you're implying here that Drake never thought that the Kuma he's fighting is the original one until he saw it bleeding. I think, given the fact that Drake's a supernova and quite knowledgeable about the secrets of the marines, he should be able to tell which is the original and which is not immediately.
Uh… How was I implying that? You only got to that conclusion because you apparently think that the one fighting alongside Kizaru is the real one (correct me if I'm wrong; I bolded the line that implies this), which is highly unlikely since the Shichibukai should be gathering to fight Whitebeard soon