This really is the "lowest hanging fruit" of the construction industry.
Did the tolerances truly need to be so tight? Probably not, and just set so by a designer somewhere. But the panels do have to line up for tying into conduit that goes to (pad mounted) transformers and distribution equipment, etc.
What I meant was, for something like a building, the plan will describe the invariants of the design, but what it really reveals are all the available variants in achieving that outcome on the actual site. With a solar farm that available variance is actually very small because the overall "plant" has very little additional or emergent structure.
This is somewhat like AVX - it only works if you have large enough vectors (a simple operation that is repeated a million times on contiguous data). Arbitrary buildings are much harder to optimize.