WOW! I'm no expert but sounds like he is extreme. I've also heard that females can sometimes fight but I have 3 females and they have never fought or showed any type of agression maybe because they're related.
OMG! Yorkies can not wear collars only harness. I've always known it was bad because it pulls on neck (collapsed trachea). He should know this!!!
I wouldn't let him near my yorkies
He seems like a Jerk!!!