I don't think it's smart, because it makes the hospital such a vulnerable target, intentional or none. If something terrible happens to it either via a dark wizard attack or a natural calamity that makes it unstable/inaccessible/etc for the moment, then who else have wizards got? I'm not sure the benefits of a centralized system is worth the catastrophe that might befall patients in case the hospital becomes unusable. The wizarding world has advanced transportation systems that can make transfer between hospitals easy anyway.

Evyclaw