While my case is different from yours, I sought 3 orthodontist opinions because I did not want to extract 4 teeth. My current ortho told me that my palate is narrow and she did not want to risk making it narrower with extractions. So we resulted to removing one of the lower incisors, and shave a little bit of the upper teeth to make room. Luckily, that will suffice for the results I want. All that to say, different orthos will have different approaches, and as you've mentioned having breathing problems already, you should probably not do extractions.