Hi Kat, Stimson's occur in differing localities all over the country except Tazzy and Victoria. A locality Stimson means that it shows colour and pattern traits from a certain locality ie; Broom, Pilbara, Windorah to name a few. Expect with the best of care that they can live + 20 years.
The simple answer as to whether you can breed a Broom locality and Pilbara Locality together is yes all the localities will breed together. Should you and what would you call them? Honestly that is your call, your animals your call. Myself I would not breed them together. I prefer to keep the localities pure, par-say, there are refinements you can make within each locality by line breeding. The reason I would keep them pure is that there is no real reason to cross them, I'm more into refining pure locality types. Biggest reason as to not mix the localities in my opinion is that down the track locality crosses, no matter what you sell them as, may eventually just be passed on as one locality or the other. The person buying them them believes that they have a certain locality and they breed them, pass on the crossed offspring as pure locality etc, etc, as you can see if this occurs often enough, and it does, soon we'll really not know what is a pure locality type.
What should they be called? If you must broom x Pilbara's.
Hope this helps