No portion of the ACM definition requires position or attacking a specific "part [of the circle]," as you stated (see the bolded portion of your reply). Since you agreed on the definition, you must prove where the definition states this is a requirement of showing skill. The burden of proof is on you to prove otherwise, not the other way around.
If you need me to prove the obvious, lol, ok.
360 degrees of target is a larger target than 5-10 degrees of a target. In layman's terms, since you need me to say it, hitting a one, window barn
anywhere vs.
the single window on the barn, only in our case, the barn is moving the window away from you.
Its easier for you to hit the the moving barn anywhere on it than to hit the single window while the barn is trying to keep it away from you. Maneuvering for a firing solution on 360 degrees of a moving target is easier than maneuvering for a firing solution on a specified 5-10 degree area of a moving target (Edit: which is EXACTLY why the USAF encourages front quarter shots. Its easier and they don't want pilots to die). I don't feel like that was much of a brainbuster, however, you've been obliged.
The question still remains, is HOing wrong or right? And the answer is.....it depends on your personal goals. It just takes less skill as defined by Fulcrum's charts and your ACM definition.
EDIT:
Quote from: Skyyr on Today at 09:39:50 PM
Air combat manoeuvring (also spelled: air combat maneuvering, or ACM) is the
art of manoeuvring a combat aircraft in order to attain a position from which an attack can be made on another aircraft
The point of ACM is to kill the opponent. Flying for any other purpose is not ACM.
THE definition. Not YOUR definition. Key word, maneuvering.