To refine the suggestion from my round 6 post:
System now: Salvage 6 cards on a win (or something like that, I'm typing this from memory), discard a number of cards on a loss, which increases as War goes on. Teams have to field a certain number of team players each round depending on their number of cards.
My suggested system: Salvage 6 cards per win, discard 6 cards per win, both increase by 1 each turn. The bar for survival starts at 30 cards and increases by a certain number; this certain number is 20 and increases by two each time a round goes by that doesn't eliminate a team (Ties are determined by a seperate set of matches between tied teams). Teams can choose how many players to field.
(As long as the warmasters avoid injecting cards into the system, it should not have problems with time length.)