So the Constitution class had never shown dorsal phasers. Assuming TAS is canon, they do. I'm not trying to open up Pandora's Box, but isn't TAS not considered canon?
TOS never showed
the port, starboard, midships and aft phasers, either. Are you asking if the ship has a giant blind spot shooting upwards or are you just trying to pin down where the phaser emplacements are?