Looking at this season for example how many of the eg. 6 worst teams are truly in tank mode (supported and seriously practiced by the coach and players). Iam hard pressed to point to any including the Bobcats and the Raptors. The tank nation is us the fans and the 6 teams are just plain bad. I will say though that BC was quite purposeful in choosing this roster to facilitate a bad season while the Bobcats theoretically could have been much better than they have if their 2 high picks (Biyombo & Kemba) played at a higher level.
My suggestion would be to eliminate the weighting (have a straight lottery) amongst the worst 4 teams, retain the weighting for the next 10 and then by record. My hope is that teams will find their natural level of competence without an incentive to play badly except maybe at the very end of the season when jockeying to get into the worst 4 group might occur by those on the edge. No incentives/guarantees for the top picks.