In your example, there are three possible outcomes:
1 > The British warships kill ALL the German fighters. RESULT: Invasion of Denmark by Britain proceeds.
2 > The British warships and German fighters wipe each other out. RESULT: US transports left in now friendly sea zone 112. Invasion of Denmark by Britain proceeds.
3 > The German fighters kill ALL the British warships and at least 1 fighter survives. RESULT: US transports left in a hostile sea zone 112. While German fighter is defending and thus can NOT hit US transports, landing of British troops in Denmark is prevented by that German fighter. INVASION CANCELLED.
What is worse, now you have a stack of defenseless US transports loaded with British troops very close to Germany and the US doesn’t move again until after Germany does. Unless Britain has something to put up there to protect those transports, 1 German plane can fly there to destroy all those US transports and UK troops with ease.
