Dog psychologists have simplified dog behaviour to the point that we think everything is as it should be as long as our dogs behave to a sterotype. The truth is that our dogs really are wolves in the living room (Desmond Morris, I believe?) but we have simplified wolf behaviour far too much. There is nothing unusual in a bitch using her urine as a marking signal - as long as you have control you should be proud that your bitch is confident and secure.
Bitches that don't mark are equally fine as long as they are confident with the position they hold.
The absolute key to dog training is not a formula you can learn - there is no magic way - every dog is an individual, a new mind to connect with. What is unwanted in one dog is the very thing you try to encourage in the next.