As I was typing this post up, I just realized that the highest Cunning we have is Shieldwing at 0. So the most observant dragon in the clutch is Shieldwing. It also means the best dragon at [i]misleading and tricking others[/i] is also [i]Shieldwing[/i] xD

Though now that I think about it, it's kind of strange that the Trickster gets a -1 to Cunning, I would have thought Cunning would have been their 0 stat rather than Courage.