I think it's:
1) Harvard/Stanford
2) Wharton/Chicago/Columbia
3) MIT/Kellogg
or simply:
1) Harvard/Stanford
2) Wharton/Chicago/Columbia
MIT/Kellogg
I do not understand the mentality that W is at the same spot as HS. Let's be real. Harvard and Stanford are WAY above Wharton. I do not know anyone who would reject Harvard or Stanford for Wharton. I'm going to Booth and in ASW I met a ton of Wharton admits who chose Booth over Wharton. I did not meet anyone deciding between H/S and Booth.
So I would say Wharton is closer to Booth than it is to Harvard and Stanford. These two are on their own league and people choose S over H and vice versa based on personal preferences all the time.