The lore for Puks when they were added in Aht Urhgan was that they were one of many types of chimera (dragon and some sort of vermin). I always took it as that's the only reason Beastmaster can charm them is because they are part Vermin. It would be in SE's best interest just to re-categorize them under Vermin and end the dispute/potential for Puk jugs. It makes me wonder though if Killer Instinct works with a charmed Puk.

Full blooded dragons in my opinion do stray too much into Dragoon territory. It was always denoted in the lore of the game that Undead, Dragons, Arcana, & Demons were in a class of their own of being more sentient, hence why they could not be easily tamed. Each of them already have their respective "knights". I personally like Beastmaster just fine as being a "knight" of the 7 common creature types. I just wish Monster Correlation and individual pet identity was more applicable, among other things like just raw damage/utility increase.