With the old rules, it meant fun for the three people picked by the leader to launch the attack that turn (and if Anir
was on the team, he'd probably be one of them), with the rest thumb twiddling. I'm all for strategic use of your best people for the key missions, but if there is only one mission, then there's no secondary objectives for lower tier players to cut their teeth on.
Perhaps balkanising the game would offer a short term fix- if you have loads of factions, then it doesn't matter so much that only 2 or 3 people per faction are fighting in a particular turn. With lots of little factions slugging it out, you might also have a longer contest (didn't the last round last about one afternoon?) with a lot more politics as different groups ally up and backstab each other in pursuit of final victory.
Of course, if the factions are too fragmentary, they may not have people around at all times for the campaign and so lose their entire territory when they've gone to bed or out for drinks which isn't much fun.