Hi , I have an 8 week old male german shepherd. He already shows himself of being very dominant and stubborn. Is this normal of german shepherds? He gets even more aggressive when you try and correct him it seems. As well , he doesn't like to be held belly up in a submisive posture and will flip out . I was told to do this though and not to let him go until he quitens. Is this a good idea or is this going to give him more of mad on in the future?Any opinions and comments are very appreciated . Thanks.