Both BWT models were submitted with 11 turret hardpoints, which allowed the new models to have the same turret coverage as the old one.
The current ship entries ingame seem to be using only 9 of those hardpoints, which would explain the reduced firepower. Since the hardpoints are already in the .cmp, it'd just needs one of the balance devs to list it in the .ini and the new BWTs will have the same offensive balance as the old model.