I have noticed over time that the Comfort+ and First Class upgrade lists generally do not seem to align. I would assume that time of request (e.g., when ticketed or when requesting a Comfort+ aisle/window at check-in) would be the tie-breaker, but the delta between the F list and the C+ list is greater than I would expect.

For example, on my flight for tomorrow, here is the upgrade list. I have bolded the names of the people on both the F and the C+ upgrade list. I have only included the first 11 people on F (there are currently 44 checked in and rising).

First Class:
1. Person 1
2. Person 2
3. Person 3
4. Person 4 (Me)
5. Person 5
6. Person 6
7. Person 7
8. Person 8
9. Person 9
10. Person 10
11. Person 11

Comfort+:
1. Person 4 (me)
2. Person 2
3. Person 9
4. Person 10
5. Person 11
6. Person 3

I have always assumed that the C+ upgrade list follows the same priority as the F list. But this doesn't seem to be the case. I can't think of any way that Person 3 can be both simultaneously above me on the F+ list and simultaneously below Person 11 on the F list. This would theoretically require (if I understand the upgrade priority to be correct) that the only difference be that Person 3 ticketed earlier than everyone else but didn't request the C+ upgrade until later, meaning everyone else from #2 on the list to #11 on the list is exactly the same as me:

1. Diamond Medallion
2. Booked on an H fare
3. Delta Reserve Card
4. No MQD waiver
5. Corporate booking
6. Tiebreaker - time of request

I just can't believe that this is the case.

Does anyone know how the C+ priority differs from FC priority and what would drive this difference?