Fuel was probably just as easy to take down in WW2 as it is in AH, apart from that in WW2 the ack wasn't as good as AH and in WW2 they were probably more interested in damaging aircraft which would have been a more viable target - planes take time to be repaired/replaced whereas bunkers are easily replaced.
So, in AH the fuel on a small and large base are easy to take down. The medium field fuel bunkers are well placed and very difficult to hit for a single Jabo.
To try and make AH a little more realistic, keep the existing fuel bunkers but introduce mobile fuel bowsers scattered around the airfield - these would have been at Bulf Fuel Installations or dispersals in WW2. How many? Not sure! 3 or 4? Perhaps even introduce a fuel bowser that you can spawn from a nearby V base and refuel aircraft that have just spawned on the runway?
Also since in WW2 there would be several aircraft scattered around the airfield on dispersals. These aircraft would already have fuel in them. So, how about even if the fuel goes down to 25%, you can still up a set limit of aircraft with 100% fuel to represent the aircraft that would have been on the dispersal? How many aircraft? Say 3 aircraft per aircraft hangar type - i.e. field with two FHs then 6 fighters can up; field with 4 BHs then 12 buffs can up.
Any thoughts?