The MBA (MacBook Air) is a head scratcher for sure. I am looking to upgrade an early 2015 retina MacBook (rMB), I really need that second USB-C port. Back then, I passed on the MBA and went with the rMB due to the retina screen since I work with photos requiring excellent detail and the rMB is powerful enough to drive the software. With the rMB, I gave up the mag-safe charger, 2 USB ports, SD card slot, lightning connector, and larger size for the hi-def screen and slightly more portability.
I went to the Apple Store and the MBA screen is noticeably dimmer, much more so than rMB, and very pronounced. It's a MBA deal killer for me. My only choice is a 13" non-touch bar Mac Book Pro (nTB MBP) with a much higher spec screen brightness. The 0.25 pound weight difference is negligible.
To me, effective positioning of the MBA within the line up is really simple. Let the MBP and portable rMB be the wireless, limited port models as they exist with different missions. Position the 13" MBA with updated retina screen as the student or old school oriented throwback model with mag-safe, USB port, and 2 lightning ports and confusion is eliminated.