FT-Battleship designs

Thinking about my original post, and some of the replies I`ve had, I`ve
come to a concusion (of sorts).
Turrets
Must have a separate hull from the mothership (and armour). Protected by
ships sheild. Mass of hull cannot be greater than the DP of the ships
hull. Minimum of 10% of turrets mass must be turret hull (just like
ships). Must mount a power system for rotating turret, at a mass of 1%
of the turret for each arc covered minus 1 (gets 1 arc free). Can carry
any weapon as for the weapons mass for single arc for that weapon, but
can only fire thrugh the arcs covered by the turret, and the turret can
only fire at 1 target per turn (cannot split fire of a single turret
between different targets, even if they are within the same arc as the
turret is firing). Turret can point in any direction in a turn, but in
only 1 direction per turn, doesn`t need to be specified until firing.
Cost is as a normal ship`s systems (ie-hull, drive/rotating equipment,
armour=x2 mass). Doesn`t have to pay for base hull cost (payed for when
building the entire ship in the first place).

I think the above is ballanced by the extra flexibility in limited arc
weapons, balanced by the vulnerablities of the turrets to incoming fire.
It would take more dammage to be inflicted to force a threshold check on
weapons mounted in the hull Vs dammage required to dammage/destroy a
turret, with all the weapons mounted within. The biggest advantage i can
see is in the reduced cost for the extra arcs, but turrets arc very week
to incoming fire. For example-

Turret with 3x Cl3 beams
Turret mass=25
Turret cost=62
Hull (turret DP)=8
Armour=4
Cl 3 beam (1 arc) x3=12
Rotaing equipment (5 arcs/4% turret mass)=1

Cl 3 beams (5 arcs) starship mounted
Weapons mass=24
Cost=72

As shown above, the turreted ship is 10 points cheaper, but only
requires 6 DP to be inflicted to force a threshold check against a
turret. 

Any comments?

BIF

"Yorkshire born, yorkshire bred,
strong in arms, thick in head"