Dr Teng's program (Las Vegas)

In talking with Dr Teng, my Mrs was told that Aetna wants 6-months of pre-surgical work (diet, exercise, NUT, etc) before submitting for approval. Now I checked the Aetna bulletin on first-time bariatric patients and their program requirements are 90 days.

How do I convince him that we only need 90 days without stepping on anyone's toes? I totally respect his opinion and have no doubt he respects his patients. I'm quite certain he also has dealt with Aetna before (he has) and knows them well. He has his own office program for the VSG (well any bariatric procedure I surmise). The NUT is 3 consecutive months, he wants to see us every 8 weeks minimum, a therapy group and some sort of physical fitness regimen.