Less water damage in wet over wet layouts
The reason that apartments of the same line are almost always stacked on top of each other in identical, or near identical, layouts is because it helps the building keep plumbing lines straight and orderly.
More importantly, less water damage is likely to occur if a water leak occurs over a wet area. For example, most bathrooms will be tiled with drainage and will be more water resistant vs a living room with parquet floors.
Furthermore, having a stacked layout across the building makes it easier to identify where leaks are coming from. For example, your neighbor will more easily discern which unit a leak is coming from if all the layouts are stacked vs varied.