>>11009140A lot of ship designs in gundam (maybe with the exception of the Salamis Cruiser and Magellan Battleship) make no sense practically. It's all cool factor. Take a look at the Musai cruiser for example (my favorite one despite its flaws.)
It only has three upper particle cannons and two torpedo launchers for weapons. Its rear and underside are totally undefended and its engines are at the end of thinly armored stalks.
