Note also that broadside combat were for sea ships because of the cannon placements on boats. There were still cannons sometimes in the forward and back but they took up a lot of room.
In space it is now not in one plane but infinite planes.
Plus the way you mount these guns it makes sence for them to have wide arcs and not small ones...
Im curious how haste is going to justify this broadside change because to me at least it makes less efficient sence for this combat system to happen.
But hey.. There are some examples like the shire that have a kinda broadside setup. One of my fav transports because of it.