[Ruy Horta]

The strength of fighter command and its radar network were inforced by the geographic position of Britain.

Fighters became the first line of defence (for lack of major german naval activity), its a unique situation for Britain, you cannot apply its variables on a one on one basis to another belligerent

Now think of France with a similar effective air defence system, yet no channel to protect its borders? The battle on the continent was one of armies and tactical aviation, not one of strategic air defence. The first line of defence was formed by divisions of infantry, tank regiments and supporting artillery, of aircraft used in a tactical role supporting the armies. The Battle of France poses a different set of rules, period.

The whole concept of British air defence is basically built upon the island fortress, the RN protecting the sea lanes, the RAF the air. Britain could always fall back, fighting on the seas and the periphery, waiting for the USA to join the fight at some point (if only to ensure the return of its loans etc in a post war world).

British focus on air defence, although effective when it came to home defence, made it impossible to really commit themselves to a continental war, always retaining one foot at home, recipe for defeat in 1940.