More than likely it has to do with when he created the teams. If he created them several days ago then the team members have all had the chance to move up and down in ranking and score since then. If that is the case, then you cannot put the blame on him. All he can do is create the teams based on their scores at a certain moment in time. After that you cannot expect him to readjust them every single time a player moves up or down in rank. That is ridiculous.
I'm not saying that is the case, he may very well have messed it up, I have no idea. But don't get too worked up over it right at the start. I know for a fact that when I was paired with my partner I was at least a Corporal, but now I am a Private First Class and will more than likely be far lower than that by the time these games actually start.