Stagger Timer by Town Hall Level
I understand what Supercell tries to do with the timer. They want to challenge people to produce enough DPS to end a game quickly. Oftentimes, an extra 30 seconds is the difference between 2 stars and 3 stars.
So let's look at some stats and numbers here. If Supercell wanted to make wars and general gameplay more interesting, they would try to make it so that 25% of attacks are 3 stars, 25% are 2 stars, 25% 1 star, and 25% failed attacks. This would show the perfect balance of offense and defense. The problem now is that 3 star attacks are ridiculously common in lower town hall levels and annoyingly rare in town hall 10 and 11. So in order to compensate for this, and in the spirit of more interesting and competitive gameplay, I suggest this:
Supercell should stagger the timer based on town hall level:
Town Hall 1-5: 2:30
Town Hall 6: 2:40
Town Hall 7: 2:50
Town Hall 8: 3:00
Town Hall 9: 3:10
Town Hall 10: 3:20
Town Hall 11: 3:30
This is based on the level of the Town Hall that is DEFENDING.