They must be using '70s-era floorplans as reference, before spaces were amalgamated for larger stores. That would also take into account the Phase 4 section of the mall that was, until the relocation of the market stalls, crated up behind drywall. Those stores would not have been inventoried as available retail space, however, so that wing's square footage should be factored into Yale's glass half-full/half-empty math.
As far as JS retailer count goes, the
Wikipedia count is under 160. For sake of comparison, Lime Ridge houses around 240, Eastgate around 100. (All of those numbers take into account stores and services -- food court vendors and kiosks.)