According to Pokedex entries, Dragonite is very fast and agile despite how bulky it is. It can even fly around the planet in sixteen hours. It may also be referring to the Dragonite from the first Pokemon movie, which acted as a deliveryman of sorts, similar to Aya possibly delivering her newspaper to anyone who'd actually want it and most people who don't want it.
As for Scraggy, I have no idea, and I'm certain some kindhearted individual out there will give us reasoning other than "It's a cute Pokemon."
Looked up some stuff about Scraggy, but nothing seems to link it to anything Tengu. In fact, it's speed is kind of medium-low. The best I can figure it, the red scale on its head vaguely resembles a Tokin hat.