I think this response more than most shows how shallow your reading and research is. Radar warns you about the initial build up of the forces, this gives you time to ready your defences. It tells your the direction the forces are coming in from and an estimate of the numbers involved. It gives you a good idea which are fighters and those that are bombers which need more concentration so you can concentrate your forces. It enables you to intercept the incoming forces before they reach the coast and once past the radar installations the Observer corps took over and generally did a good job. Few, very few raids reached their target without warning.
I shouldn't have to say this as its basic A, B, C, stuff of radar and its use. Someone who says so much would have known this and I find it disappointing.
As for his military career, you do know that he was badly gassed in combat and had two mild heart attacks probably the result of his injuries. Was he perfect, No, did he blow his own trumpet, yes so did others, Montgomery, Patton, Clark, MacArthur, to name but a few and I have no doubt that others could easily be added to the list. Were they all incompetent, no.
You can look at what Mearsheimer said about him and you could also look at what Richard M. Swain said about those comments.
Did Liddell get everything right, No, did he get more right than he got wrong, I would argue yes. Calling a man who served well and with considerable success a fool is a strong statement. Interestingly it was one of Liddells main theories that infantry should be carried in protected vehicles with the tanks, which is a basic structure of nearly all modern units Excepting specialised units. Not bad for an im,poster in the 1930's
If you are talking fools, you might want to consider your comments about the US Marines starting from the Shetland Islands, invading Scotland, marching onto London and starting a second front. All the time on the presumption that the Battle of the |Atlantic had been lost.
You have heard the phrase, 'People who live in glass houses shouldn't throw stones'