So, after being put onto looking at your accepted list, I think I definitely have a fair idea about the two schools you're referring to for arch/anth. It's come up for discussion in my experience as well: what is the new layout going to be with all of those new hires? I don't know whether to think it's a negative or a positive thing: either it's a sign that they needed revitalisation or it's a sign that they have a great commitment to the field in the future?
You hear a lot about finding a particular person that you're interested in working with for a successful graduate experience but that can always backfire as academics (especially young ones) move around often - as you've discovered. Is there a way of contacting your POI about it, given that he has had dealings with both institutions? He'll be able to give you an idea of both programs and the potential strengths of each, and also the atmosphere (or change in atmosphere) at School B. Of course, he may be totally biased ("come work with me!") but he'll know that there's a lot of different factors in your decision too. Not least of which is surely geography.