Originally posted by i83N it’s not so hard to trained your brain to remember that in landscape buttons are in one place in portrait in another.
The Nikon D4s that I work with has the AF-on button in exactly the same place in portrait or landscape orientation*: it makes sense.
Asymmetry in the control scheme with critical functions nearly always causes problems. Truth be told: people can adjust, it is simply a matter of time and practice.
* it was moved there due to complaints from D3s users. On the D3s the AF-ON button was placed to the left on the rear control dial on the camera body, but in portrait orientation: the AF-ON button was placed above the control wheel, which made it easy to accidentally change exposure settings. The pentax K10D has an AE-L button that fits right under the thumb on both the body and on the grip, the green button are both in the same place, on the left just behind the shutter. The EV compensation on the K10 grip was placed in a weird spot though.