Here is one possibility: if the subs are close in skill to the starters, the subs will play more. if there is a great discrepancy, the subs will play much less. If the sub is actually better thanthe starter, the sub may even play more minutes.
I think this is absolutely incorrect for this season.
(75703499) - Note the SG position in this game
I had trouble with subs in each of the SF, PF and C position getting too many minutes and the subs not coming in for very many minutes at all. Granted the starters at PF and C are much better than their subs. However at SF, my starter has a 37K salary and the backup 35k. The backup has also had a few pops already this season and has about 15 tsp more than the starter.
SG is the real point I am making here
starter -
(27779921) 11K salary played 38 minutes
sub and reserve
(27253055) 40K salary and only played 10 minutes. (granted this is twice as much as any other sub got)
This ratio in the past would have been typical split for a more normal starter and good reserve. But as you can see the sub has 4 times the salary and 35 more total skill points than the starter. Strictly follow depth chart is a little out of whack this season