Hmm, i've been thinking about it all day, and i think 1 nice solution will be the next:
-8 teams of 2 guys, 1 captain on each team, wich is permanent(so here comes the more active guys).Second slot goes to free agent, wich is a partner(there goes the people who have less time to spend) who can be chosen on the list of players, each 2 duels free agents can be changed and are avaidable for hiring.So, the 8 teams duels each others, and the 4 with better stadistics goes to a playoff semis.And ofc the winner comes from that elimination.So that would be 7 fights, and if u have luck 2 more.Everybody takes part in it, the more active guys and the ones who have a real life.What you think about it?