Commission group priority

When adding a commission group to a campaign you may see the following window:


There you have the "Priority'' field. Now you may ask: "How does it work, when does it apply?"
Here is the answer:
Let's  have 3 commission groups:
CG1 - priority set to no. 1   -- lowest commissions 
CG2 - priority set to no. 2   -- higher commissions
CG3 - priority set to no. 3   -- highest commissions
Let's have 3 performance rewards:
PR1 - at the beginning of a month puts all the affiliates to the commission group CG1
PR2 - puts the affiliate to CG2 if number of sales in actual month is higher then 5
PR3 - puts the affiliate to CG3 if number of sales in actual month is higher then 10
The above mentioned settings would work in a way, that each month every affiliate is put to CG1 and according to the number of referred sales they may get into a commission group of higher commissions (CG2, CG3). So the priority has nothing to do with it so far.
But let's assume you have a good friend (Mike) and you made a deal, that he does not want to get back down to CG1 anymore even if a new month starts. So once he reached the commission group of CG2, he does not want to be put into a 'lower' commission group.
But how to decide which commission group is lower? Here comes the priority while the higher number is the higher priority (higher commission group).
Therefore you  set Mike's  "status" to 'Ascending':
and if he once reached the commission group of CG2  with priority no.2  he would never get to CG1 (priority no. 1), but would stay in CG2 or promote to a higher commission group.
In conclusion, the priority makes sense if in the particular commission group an affiliate has Ascending or Descending status.