history of top fraternities

I am not in a fraternity but observe from the outside. I have many friends in the top ones and this is what I observe:
1. Sigma Nu: Have the best alumni out of all frats. They got completely kicked off in 2007 and came back surprisingly strong. That is b/c of their alumni. Many people say they are not involved on campus but they were named chapter of the year last year and continue to have guys in Blue Key, Tiger Brotherhood, SAC, etc.
2. KA: Have a lot of money but there alumni isn't as close or involved as sigma nu alumni. In years past, they have been the best but with recent pledge classes they move down a spot.
3. ATO: Don't have a strong alumni, have been involved in many different organizations like sigma nu. Don't know their young guys.
4. Sigma Chi: Have no clue what alumni is like, but they recruit well and have big parties.