So, to summarize, the advantage of PM/gifted FO would be the waived change fees on award tix ($150 per ticket).
For 2015 the RDM earnings would be equal if we fly together on the same fares (9+7 vs. 8+8 miles/$).
The advantage of two GM would be waived SDC fee for the FO ($50).
Upgrade priority for PM>GM>FO, so the chance of a single upgrade is higher, and two upgrades would be lower.
Am I missing anything?