I think they are jealous that your dog is tougher than their dogs!!!

Ok this is just my opinion. I dont take time trying to change the way my dogs act, I only try to control it to an extent. Bella is VERY aggressive that just her personality since day 1. Its not an issue she has never hurt anyone but acts like she will eat your face off and takes no crap from anyone. Diggy is more laid back and takes a lot of crap and thats just him. I think Yorkies are all unique and as an owner of 2, I try to let their personalites flourish. Unless of course it gets out of control then i step in. Who cares if they "like" Barkley if your happy and he is happy then let him be BARKLEY

Good luck with classes