I also just read the article you shared. That is NOT what I am referring to when I say 'pack leader'. I'm not referring to abuse, dominance and scaring a dog into good behaviour.
I'm referring to not letting it eat from you when you're at a table, not letting it sit where humans sit and sleep where humans sleep, not letting the dog decide when it's going to do things for example pushing you off a sofa because it wants to lie there etc. Just basic situations where you let the dog know it's infact a dog and not a human. Letting them know that they're not the 'boss'. I'm not saying physically abuse them when they do these things, but most definitely punish them in a suitable way. Otherwise, in my opinion, you are going to end up with a dog that thinks it's in charge and that could be very dangerous.