MadMonkey: Working from your idea, this is what I see:

Each fellowship has 1 team of 6 players in the stairs. Or beter yet, maybe 7 players, that way there will be less ties. But getting 7 might be hard for some fellowships. Maybe 5, but allow fellowship to enter 2 teams for those who have a lot. But now I'm getting into more work for Fencer.

Since it's backgammon, I would say just do a 1 game per 2 players.

Each team captain can challenge 1 team, and can also be challenged by another team. So no more then 2 team stair matchs can go on at the same time. (like current stairs)

The players on the team when the challenge started stays until that match is done.

I'm not sure what I like beter:
1) Limit a team to changing 1 player once a month (or)
2) A player has to stay with a team at least a month before they can be removed or leave. (which means every month, a fellowship could technicly change their team completly.

I kind of like #2 beter since sometimes you will get a few people who will all of a sudden not want any more games and may need to be replaced.

Of course the extra rule would be that if a person drops their membership to a pawn level, they can be removed and replaced right away without the limits above getting in the way. (*** When I say right away - they can complete current games, but no new challenges can be made or accepted until the pawn is replaced by a knight/rook fellowship member ***)

Other then that, most of the regular stairs rules would work. The time limit of 4-5 days I found work for the majority of players (a few find it too slow, a few find it too fast - but most find 4-5 days pretty good).

So this is my more complete thoughts about MadMonkey's team stairs.