The P-47 feels quite awkward for this map, due to visual range and the speed of the plane + it's slow maneuvering speeds..
The view distance can be increased if players keep having problems with flying.
So for the allies "historical accuracy" is used..
The 76mm Jumbo was indeed replaced with a regular Jumbo because it was too rare. However, I can imagine that another Hellcat could have the same impact on the balance of this map.
We had small discussion on Hslan on the other day. So, why the planes?
You have to understand that this map is not just about the siege. It's about the entire battle, from the fighting that took place before the 101st even arrived to the US counter attack that lasted until January. During the first days the weather was bad, that is true. But later in the battle the weather improved and the P47s flew whenever possible.
I tried to recreate this by giving the US team planes that spawn only after several flags have been captured. And the German plane represents the bombings that the Luftwaffe carried out during the battle. I'll admit it's still debatable how many planes should be on this map (if any). I think the current amount is reasonable at least.
(one of the sources I used:
http://en.wikisource.org/wiki/The_Ardennes:_Battle_of_the_Bulge/Chapter_XIX)