Ooooh! What a fascinating headcanon!! Kakashi teaching his dogs to talk aaaa ;//u//; that’s adorable!
I actually harbor a minor headcanon that Rin is descended from either a bastard or tangential line derived from the Inuzuka clan, inspired solely because of her face markings. Which ties into my other headcanon – she left the nin-dog summoning to Kakashi in her will :V She had planned on mastering the technique to train therapy-related nin-dogs after the war, but never got around to it.