All ranks are biased. But I don't think four universities from UK can make into top 10. Cambridge and Oxford maybe, the other two not so much. Regarding the rankings from ARWU, I think Berkeley and Columbia is a bit too high on the list.
Berkeley has a hudge breadth of top ranked Phd courses, so depending on how you account for that it matters greatly. It also has a surprisingly strong brand internationally, including in Asia. So, smart people think differently depending upon where you are getting the data from. (What USA tennie-boppers think is "prestigeous" doesn't always play well in other areas, etc).
I agree about Berkeley. Looking over the various departmental rankings, Berkeley and Stanford are the only universities that (at the PhD level) seem to be near the top in every discipline.
I'd guess that the absence of a med school pulls down Berkeley's ranking somewhat. When you start comparing research funding and activity, the med schools play a huge role in pumping up the numbers.
