Yeah, it seems obvious to me a lot of choice of location and choice of field factors are involved in these rankings. I have no idea how to reliably control for all that, which is part of why I tend to have low levels of interest in rankings like this for actual college choice purposes (for other purposes I think they can be quite interesting to consider).
By the way, WashU recently announced it was acquiring the St Louis College of Pharmacy (actually the whole university, but that is the component that will persist as a new WashU school):
Hidden agenda to increase its score on some of these metrics? Almost surely not, but I find it an amusing thought.