Apple have created a mess by providing multiple options between Airs and Pros. If you upgrade the RAM to 16GB on Air it surpasses the base model of Pro and similarly other storage options. At that point you should rather buy a Pro over Air because the only major difference is size. Lot of this is totally confusing for non-technical folks and they might just end-up making a wrong purchase.
In Singapore the difference in price between cheapest Air and cheapest Pro is less than SG$100 (US$70). The only advantage of Air is longer battery life, but that's it.
I think at this point the Air series should be merged with MacBooks. Make it small (12"), give it one more USB-C port, upgrade processor, add TouchID and it's good to go.