When the season long fantasy first idea was first created, it was similar to what you are suggesting. We picked 4 teams and had their scores average based on the number of regionals they attended. The only problem with this is that it took forever to score and there was faulty data for some regionals.
2006, run by Billfred
2007, run by Koko Ed (won by yours truly)
I loved the way these drafts were run and I would love to see a return to this system, I would help someone run it if they would do the scoring.