One would think Flint would have learned to take credit for other people's achievements, thus being the public facade of da Vinci even if another Leonardo did the actual work. Then again, Flint knows how to operate from behind the scenes: perhaps he never was Leonardo da Vinci, but merely did most of the things Leonardo is credited for. "Credit" remains quite ambiguous until the 19th century anyway.
Personally, I don't have a problem with this. If Flint was two or three dozen human celebrities, so what? Mankind has produced tens of thousands of those. Flint isn't really making a dent there, he's just blending in. Indeed, he couldn't pull it off if mankind weren't in the habit of producing geniuses and wunderkinder of all sorts already.