What I have discerened from the information presented so far is that the point is very simple: Replicate the effect of normal mapped surfaces on the PS2. And it seems that they have made an arbitrary algorithm to do this with polygons while avoiding the cost of unnecessary polygons. The point is that a floor like that is probably normal mapped in the Xbox version, so their "geo texturing" does the same with polygons. I think the number of poly's in the tile is really irrelevant as long as the their method works successfully.
This is all IMH(umble)O ofcourse.
This is all IMH(umble)O ofcourse.