Buzzy,
I believe your coach came with Dometic air conditioners. They do not rate them on CFM (cubic feet per minute) They are rated on cooling capacity (BTU) I would replace them with 3- Dometic air conditioners rated at 15,000 BTU each. Replace the current thermostats with the 10 button models. Make sure the technician knows how to program them properly so they "see" each respective zone. You will enjoy your coach in Phoenix AZ in the summertime! Regards, Fred