This is interesting a test, it is easier to relate to other humans indeed.
I’ve been trying the A320 in 2D a few days ago for comparing some other things and this strikes me: in 2D the cockpit size feels real when panning around. I’m starting to think they might have voluntarily oversized the A320 cockpit so that when seated at the expected position, the range of visible gauges is what they were trying to fit in the view by default. It is far fetched but it could be and it is a common technique to bend the reality to fit a game “art director view”.
Another possibility is that the variation in scale is due to another bug, which is also related to my discovery of the Trees LOD problems and the POIs popping up only until close enough:
POI Very Late Rendering/Draw/Pop-In SOLUTION FOR ASOBO TO FIX IN THIS THREAD
The root cause is the 3D models loader in FS2020 seems to be ignoring the 3D model internal scaling factors for computed the minimum distance to which it can display in view. It is possible the same loader is ignoring the 3D cockpit model scaling factor as well.
I’ve added this comment to the other topic where you can vote about this:
[FEATURE REQUEST] Cockpit Size and World Scale in VR