The problem with your scenario --> by the time the Perseus gets to 6.5km away from a Hammerhead, my Retaliator has had you locked for about 15km (or a Polaris would have you locked for ?25-30-ish km?)...in a battle, you aren't going to get that close without being a big target yourself.
At least with the Ares, you are much smaller and harder to target with torpedoes, while having the same range since your guns are the same size. Also, the Perseus is going to take at least 4 people minimum, more likely 6 to fly effectively. If the AA guns are decent, then I can see a role for the Perseus protecting larger ships from incoming torpedoes, but as pointed out above by
@Cugino83 , that isn't a great role (and likely, fighters would also be able to fill that role, when we can target torpedoes, or again, a HH would also be great at that role with the 6 turrets with the 4 Size4 guns).