Almost every scene I have been to I have noticed to be lead heavy. But I am not necesarily claiming they were. Many times the only people we see of the opposite dance orientation are those that we WANT to dance with and at the same time we see all the same dance orientation(competition) dancers. This may cause for people always seeing an imbalance going against them. I have sometimes thought a scene was imbalanced and once I actually made a head count it came out quite even and even just a smidge in my favor.