An observation I made today that may have been more immediately obvious to some others is that because the right mirror mount is offset on the front brake master cylinder assembly, it can be better adjusted for seeing behind you. I have my CT125 mirrors adjusted so that the left mirror shows left behind, right mirror shows center behind and right behind. For anyone struggling with seeing their left shoulder more than their right, I'd recommend giving that adjustment a free try to see if it suits you before buying mirror extenders, which may still be necessary for taller riders.
I think every other motorcycle I've owned has had both factory mirrors mounted centered on the handlebar, or at least in symmetrical position to each other. So I was used to having left & partial center view in the left mirror, right & partial center view in the right mirror. Both mirrors combined give a full rear view with minimal overlap.