The standard approach to orthodontics is to extract teeth to make room and then move the remaining teeth into place. There is an alternative approach which involves enlarging the jaw, either through expanders, surgery or a combination of both.
Unfortunately this is an area where the patient or parent often has to make the decision because specialists only know about what they do. As a related example, I asked a dentist and an orthodontist what was more suitable for me, Invisalign or braces. They could each tell me about the time and likely result of their own specialty, but refused to offer any opinion on what was better for me and my situation.
Somewhat related, there was an interesting article about the wildly different advice given to someone who visited 50 different dentists [1].
Bottom line is seek out multiple opinions and don't expect someone else to guide you on the bigger picture.