Maximum efficiency of airplanes is generally 5 of a given type

    • No. A 10 plane stack will do more damage than a 5 plane stack. But 2 stacks of 5 planes of the same type will do considerably more damage than 1 stack of 10 planes when an enemy timer ticks. For example, the efficiency of a 10 plane stack might only be say 70% X the attack or defense points.
      I don't have a 10 interceptor stack to give an actual value.

      For Interceptor lv. 1,
      10 interceptors x 5 Defense value X .70 efficiency x 100% condition = 35 defense value per enemy tick
      NOTE: With 1 stack, you lose an interceptor every time the interceptor hit points gets to a multiple of 20. So if your units aren't at 100%, it might not take many hit points to lose a plane. Ideally after each round, you would estimate your risk of losing a plane. if it looks like you will lose a plane, you might want to send an interceptor back to base.

      5 interceptors x 2 stacks x 5 Defense value x 1.00 efficiency x 100% condition = 50 defense value per enemy tick
      NOTE: With 2 stacks, you can take as much as 40 points damage at 100% condition before you lose a plane since the stack has to lose interceptor hit points before you lose a plane.
      Over time, you are averaging about 42% more damage which means the enemy stack will lose planes quicker and you will lose fewer planes. This would be true for other levels too since only the defensive value would change.