About that overstacking planes thing, I think defending actually works without counting SBDE, because that was how I lost to Finland that I explained in another thread.
My airforce and the Finnish airforce were about the same number, but he had stacked all his interceptors and tacs separately (like 1 huge stack of int and 1 huge stack of tacs). Mine was in the SBDE 5/5 formation. We both had our patrol, but he constantly moved his airforce to either attack my ground troops or to evade my airforce. I go to sleep even though I had tried my best to minimize losses (the battle began near my bedtime), and I wake up finding the Finns losing a few planes while I lose all of my airforce. I'm not sure if this is detailed enough, but I think it's evidence that when planes are defending, the SBDE doesn't count.
