Does the USGA and their slope/rating criteria not encourage this?
We need JV for the authoritative answer here, but from my experience just note that:
1. The general rule is that only tees more than 25 yards apart get a separate "rating", regardless of their designation;
2. This is straight-line distance, however - tees from different angles could be rated differently if they provide significant difference in obstacles faced;
3. The course would have to request such separate ratings, and it would give separate numbers. My guess at Pacific Dunes is that re #10, the obstacles faced aren't different enough to give a different utlimate numerical outcome... same would go for the two different greens on 9....
I believe the local associations will rate whatever courses want them to rate... so the basic answer here is the system works... the course just might end up with many different numerical ratings if they have many different tees, same as now for courses with 5 tee blocks - you might just have an A,B,C rating from one set of blocks....
TH