In terms of pairing, with working dogs there is always a danger of pairing strengths to weaknesses because you could end up with pups with the combination of worst of both parents. You really want to breed the best dogs to each other and have a good understanding of their ancestral makeup, not just their apparent phenotype.
You need to be able to critically evaluate their structure. If you stack them correctly and photograph them you can then place dots and join lines and measure angles. You need to understand how each dog is put together from an object measured point of view rather than the subjective view that you have presented.
So this is where you want to get your goals set. What are you breeding to produce? Do you have something in mind. In my opinion all breeders should have very clear goals about what they want to achieve and then find the right dogs to start out with.