joriss_s, I just checked your recent war.
One issue I see is you use attack helicopters with FP/drones. Attack helis only attack ground forces, not defensive helis/ints, so don't use them.
Not sure if you're doing it or not, but pick a county and attack the defenses of that county to draw out the air defense. Counties have no garrisons. Or you can pick each air wing from the target list and destroy them one by one starting with interceptors.
Also, try attacking air defense with only a wing of fighter planes. The losses should be about the same as using drones for cover, so you save money for the cost of drones. You wont lose any FPs against helicopters.
Other then that, your losses appear to be small.
I don't use ground forces here's what I do:
1 airforce attack wing=500FP, I take interceptors/helicopters
1 airforce attack &bombing wing=500 bombers, bombers attack defense of forts,cities,capitol,corporations
Then the bombers destroy the target of Capitol,cities,corporations.
I use cruise missiles to destroy the target of forts. You can use bombers but the losses are greater.