The installations I was referring to are very common and one builder had a special block made with holes in the face shell. They also had a solid top but were laid with open "head joints" on the ends to allow water to drain down and be picked up and routed into the gravel around and under the perforated PVC pipe inside the basement that was also linked to the exterior drain.
He bought reels of 3/4" (aprox.) flexible pipe that was precut in advance in his shops.
This was a standard installation in every one of the over 4000 homes built irregardless of the soil types because it was cheaper to make it a standard step and so cheap to do it when it can be scheduled in. The slabs were poured after the drainage, floor drains and other basement utilities were in.
Much of it was dictated by the speed and economics and never having a wet basement (and it worked!). Pouring the slab after the strip footings and walls were up allowed the house to be enclosed rapidly in inclement weather (-0F or summer downpours) for faster finishing.
It is a little overdone, but many other areas in the country do things similarly, especially where a "basement" (or part of it is) and for walk-outs.