What a completely pointless exercise. The Sony A7 bodies are already reasonably compact; the problem is lenses - the affordable and reasonably small lenses are generally mediocre, the good lenses are invariably huge and expensive, and a new smaller body will not improve that. I speak as an ex Sony user, both FF and A6000 series.
Not sure what your benchmark is for glass, but Samyang makes a few that fit your criteria and are far from mediocre: 35mm 2.8, 45mm 1.8, and 75mm 1.8 lenses. Their new 35mm 1.8 will also likely fall in line.
Also, if you stretch your budget a bit, and look at the used market, Sony has its own as well like the 35mm 1.8 and 2.8, 55mm 1.8. Also, the 28mm f2 is good enough in the center for many uses.
For zooms, you also have the Tamron selection, which are compact for what they offer.
I’d expect someone willing to spend $1800 on this new body, would also be willing to spend a bit on good quality compact glass.
If not, then FF is not for them and Sony has plenty of nice little APS-C bodies to choose from.