Question about geometry setting

I am building a simple geometry (1 to 9 buildings within a set plot) for simulation and I need to change the dimension of the boxes (buildings), randomize their heights and change their orientations.

Not sure if it is because I used a very clumsy way to build the geometry, the simulation runs very slow and I am still finding a way to randomize the building heights.

i would be much appreciated if I could get some suggestions on simplifying it and how to randomize the building heights.

geometry (test).gh (23.3 KB)