I don't know if this is a Top 20 statistic or not, but there was not a single mecanum drive robot on Einstein this year. I won $10 when that happened.
I bet you'll find that almost all of them used roughtop or wedgetop tread in their robot, at least 4 CIMs (I don't think any of the 6 motor teams made the top 20), and they had good possession.
I also think though, that you need to figure out what is causation and what's simple correlation.