Welcome to Yt!!! Beware of yorkies! You will most definitely fall in love!
I have 3 boys and a girl... They all get along great and luckily I've never had an alpha situation! I think (IMO) boys seem to be a bit more affectionate than females... They all have such unique personalities though!! Getting 2 at the same time could be challenging, however you would get all the training done at the same time! Please read up in the breed and know they are indoor pets, and require a lot of attention! They love their people! Good luck to you!!