One key problem in this setup is that the Axis is given aircraft that they very likely wouldn't have used in this scenario. The Germans learned their lesson, albeit too late, during the Battle of Britain, that their bombing strategy and aircraft were insufficient to the task. They were in the process of developing more capable heavy bombers typified by the American B-17s and B-24s, and the British Lancaster, but Allied attacks on their industry and the need to focus on air defense prevented these from being fully explored.
The premise of this is one in which the Allied bombing campaign stalled, if it ever got going. However we do NOT have a plane set that adequately reflects this. If history had unfolded in this manner, the Germans would very likely have access to the advanced four-engined heavy bombers they designed but circumstances prevented them from constructing, while the Allies would have focused more attention on the development of interceptors and destroyers. The Tempest certainly fits this role adequately, as would the Mosquito (in fact, I think the Mosquito SHOULD be inserted into the Allied plane set in place of one of the Spit variants). However the P-51 and P-47N do not, as they were both designed as long-range high-altitude escorts. Of the American plane set, the P-38 and F4U-1C better fit the "destroyer" role.
Also, I agree with Stampf. If the Allies had the numbers advantage while flying attack during Kanalkampf when the Luftwaffe was on the ropes, why do they have the numerical advantage NOW that THEY'RE in that position?
IMO, I'd make the following adjustments for Frames 2 and 3:
Allied Plane Set:
Retain the Tempest and Spit XIV, as she's the closest Spit available to the type of high-altitude interceptor we'd expect in this setup.
Replace the Spit XVI with Mosquito
Replace the P-51 with the P-38L
Retain the P-47N, or replace her with one of the later D variants. The P-47s aren't perfect for this setup, but their heavy machine gun armament best suits the "destroyer" role
Axis Plane Set:
Unfortunately there's not much that can be done here, as there's nothing in the Axis plane set that adequately reflects what equipment the Luftwaffe would have had in the field under these circumstances (short of substituting B-17s, B-24s or Lancasters to fill in for the planned German heavies).
Numbers:
Shift some of the Allied squadrons to Axis. As stated above: If the Axis had a numerical disadvantage in Kanalkampf and this setup is meant to reflect an alternate scenario where the Allies faced this same situation, then the Axis should have the numerical advantage this time.