The hats are ceremonial, they wear them after we (I'm British) beat Napoleon at Waterloo, defeated his Old Guard and took their massive hats in celebration :)

Its the British equivalent of drinking from your enemy's skull. They don't wear them in combat though. Similarily the British Airborne are called the 'Red Devils' because of their red berets but they wear helmets in combat, it makes a bit more tactical sense.

Also, good comic, thumb :)

What has been seen cannot be unseen.

Ive been doing it wrong this whole time!