This is just a rough concept, maybe some one can refine better who understand the game better.
During a War, when you declare a battle you also get to decide on a tactic or strategy; Offensive, Balanced, Defensive.
Balanced would be as things are now.
Offensive could increase the total # of attacks each member can make, but at the cost of increasing the timer when your bases get attacked.
Defensive could reduce the timer for when you get attacked and/or the time between waves at the cost of total # of attacks or only attack each enemy 1-2 times instead of 3.