NBL would be above the d- league, d league players come to the nbl too, and the reason so many d league players would go to the nba, is becuase it is a direct connection with the nba, a decent player in the nbl would proberly have a better chance at getting tnto the nba if they went to the d-league first. and concidering d league players get paid a third of what nbl players get paid, many players would proberly rather play in the nbl.
Also, the d league teams get a fraction of the attendance the nbl gets
there biggest team average in the d league is 4,817.
and most teams in the d league average is around 2,000- 3,000