quite a simple answer and one that i've answered a few times: i only put people in forums they applied for and the fact is, in the first group of people submitting applications and chosen almost at random (a few are being re-reviewed) not a single soul asked to be assigned to Air Canada. I actually had to turn people away from United and American and Starwood, it seems like everyone wanted those forums. I think in the next group there was one or two for Air Canada, but i'm not choosing by forum, just by people.
This also should explain why there are only two moderators in CO, one in BA and none in Marriott. It all had to do with the odds of what forums the first moderators had asked to moderate in their orginal applications. My guess is that over time and with an addiditional group of volunteers this may even out since i'll probably have to start assigning forums eventually since some of the more popular ones are sold out. But since we're trying to pick people first, it's less about which forums to me.
Sorry it is so simple.