Hold on a second.

Exhaust port is only 2 meters wide. The entire width of the nose of the x-wing can't be much more than 2 meters, but it could fire two torpedoes that barely fit through the opening.

Could Lucas have meant "2 feet", but wanted to sound more universal? That would be impressive to bullseye, while shooting wamp rats which are BIGGER than 2 meters doesn't seem so impressive (but it does sound terrifying).

EDIT: Upon review, the torpedoes don't just squeeze through like I thought they did. If the port is indeed 6 feet wide, it looks like the torpedoes are 1.5 feet or so wide. No, nevermind. Still, 6+ foot wamp rats are terrifying.

EDIT: I can't live without pictures: