Resize display in display arrangement / actual size instead of resolution

Solution 1:

Short answer, no.

'Full HD' is actually tiny compared to the resolution of a retina screen - 1920x1080 vs 2880x1800

The Displays control panel really has no idea how big the screen is, only what resolutions it is capable of.
The relationship it displays is a direct result of that - & your mouse will jump according to how you set the images of the screens against each other.
The most logical method is to align the tops of the screens in the control panel, so you at least have one matching point of reference.

I have 2 identical monitors, so it's not so easy to illustrate - but you want this...

rather than this...

The screen images will snap to 'sensible' locations, but you are actually free to position them any way you like, simply by dragging one of them relative to the other.