Very true, those fighters are very needed in Defense, as they are stronger in that regard.
Also, I did once have a sucessfull Dunkirk evacuation of my French Fighter from the French battle. I am pretty sure its a house rule, but the way we usually play is that if there are no attacking air units, then the defending air unit can retreat to a safe territory within its range if it survives the first round of combat.
Of course it did, and my opponent forgot to throw a Stuka at France, so the Dewontine came in very useful for a possible sealion defense and also to land on a carrier later on as a defender.