Star Destroyers and Calamarian Cruisers should be bristling with guns. Maybe not fifty, but they should be a nightmare to be around for fighters. I liked how TIE Fighter made capital ships and space stations truly horrific to get up close to, and I disliked how Star Destroyers were sitting ducks to fighters in X-Wing Alliance.
Cap ships should be very, very hard to take down for fighters and bombers. How to implement the many guns, I don't know. Manning multiple guns, the way you do it on Battleships in FH, has been suggested, as have auto-guns, I think.
Oh, and the Lancer has twenty anti-fighter guns, so that's one ship that's got a lot of weaponry. Just as a side note.
"One of the bitches actually gave birth while she was attacking, and her puppies joined in on the carnage."
--the awesomeness that is Boatmurdered.