>> Your energy armed ships should probably be about as fast as the enemy ships they are shooting at, so putting anti-ship weapons in turrets is unnecessary
Conversely, when I do a missile heavy game, I often let my missile ships be pretty slow (lots of space in the magazines and launchers), and let mt beam ships keep the same fleet speed, and use beam turrets to preserve the tracking speed. You do need a bit of a tech advantage I find though, because if your opponent has too much of an advantage, you won't be able to hit them or run from them