Only i think heavy transport turrets is too much? Before this beasts, pirating on fighters are hard, but now its end, maybe out or rebalance that turret? Like add more weight to them?
Traders that use Heavy Transport turrets have to give up 50 cargo space for every gun ( 12 guns = 600 cargo less ) they have more protection that way but less profit . if they also want more protection they use CAU VIII ( - 300 cargo ) . They deliberately have much less profit in exchange for protection , thats fine with me .
If you cant handle them stick to attacking Mastodons who don't have armor and use freighter shields for maximum 5000 cargo , or shift to bigger pirate ship , like rest of pirates .
EDIT :
Besides , Heavy Transport turrets are just upgraded Basic Transport turrets , double fire power-double energy consumption , Transport Charons are still better regarding firepower/energy usage .