Distributing buildings on a Lot can be done in an infinite variation, so that process is a design process. No computer and no software can calculate a 'good' solution, so I usually say all design processes shall be done manually.
--> in CE : Design --> Statistics = ok ! Statistics --> Design = not ok !
Designing is an iterative process and the CGA model generation starts at one point and ends somewhere, so you have basically 1 iteration for a given set of attributes. But testing for the 'best' combination is an endless endeavor, so CE cannot do this for you, sadly. 😉
I'd recommend you do the following :
Write some Lot subdivision code which includes convexify() and some dimension/area checks to make sure that buildings do not overlap.
From there, play with splitting these shapes with different approaches ( stripes, .. ) which give you a realistic distribution. Then, add some reporting to compare the resulting geometry values with the target values.
I'm honest that CGA is not the best tool for realistic 'per shape' parcelling tasks, but I've done some tests in past that give you good results.
Let me know if that 'theory' makes sense so far ..