Correct me if I am wrong, but the idea that NPC sororities have huge pledge classes is one of the biggest misconceptions about NPC rush. I went to a predominately white college, so I got to see some of the 'goings on' and although the Rush period starts as one big group, the pledge classes (i.e. after bids are given out) are much smaller.
SoCalGirl>The main difference between pledge lines and pledge classes are the traditions. Also, there are some schools where 50+ pledge lines are the norm. I've never heard of a line or pledge class with 200.
Like prettygyrl said, what works for some orgs might not work for the others. Shucks, what works for one CHAPTER might not work for another!
ZetaAce