Modified YT 13000 Fighter Carrier

Some time ago, I ran across this comment about how ships like the Millennium Flacon were designed to hold cargo pods within the front mandibles. While the Falcon was obviously modified for speed, I was wondering why you couldn't use that format make a mini capital ship out of it.

A cargo container permanently attached to the ship's mandibles, modified with power generators and it's own weapon systems. Sets of three access ports are set on the port, starboard and keel of the container allowing composite "Ugly" fighters  utilizing the cockpits from TIE fighters and thruster units and laser cannon from the X-Wing.