mmmh... Again, I am really pounding my head against the wall..
Sure i would LOVE to see 12 hits on that SOB... i really don't know why they would design DOWN in ship toughness all together, considering the progressive nature of their society, without some significant enhancements to firepower.
Though admittedly, a Custodian can mop the floor with an explorer on general principle.
We are pounding our heads on a razor edge. Do we give the Custodian the power of cruiser level maneuverability? Or do we call it a battleship and insist on increased toughness?
If i had my say, it would share a standard battleship carrier profile. (12/battleship, 20cm, 45 turn, 4 shield, 5 turret, 5+ (6+grav prow). While retaining it's Launch capacity 8. This would force it's point cost to increase to close to 400 points, but so what? I fail to see that as a problem, because even with this profile, it is still a weaker choice then the Chaos or Imperial battleships, while rightfully outstripping Gorbag's revenge.
Currently, it's stats are impressive for a grand cruiser hull, costed at a battleship's price. With none of the benefits. While I understand the need to clarify their current inferior status to Imperial technology, new and old, at it's current position it is WORSE then it's equivalent Ork battleship, Gorbag's revenge.
Gorbag now will have access to LOTS of new gubbin's, already outstrips the custodian's current position in hits, launch capacity, can take the new boarding torpedos, better firepower all around, can upgrade it's turrets to match, can upgrade shields to match... How do you justify this? Tau are supposed to have superior technology to orks, but inferior to Imperial Navy and chaos.
Here is my compromise, as both a battleship, and a grand cruiser.
Battleship 350 points
12/battleship, 15cm speed, 45 turn, 5+ armor, 4 shields, 5 turrets
Armament
Port and starboard st 6 weapons battery, 45 cm FL and FR respectively
Port and starboard st 1 Ion cannon 45cm, FL and FR respectively
Ventral grav hooks for 3 wardens
Port and starboard st 4 launch bays for mantas and barracudas, resulting an a LC 8
Prow gravitic launcher st 7
special rules: tracking system, grav prow, cannot CTNH
This makes the vessel a TRUE battleship, not as good as the emperor (which can load assault boats, has a much better weapons battery, and has a leadership bonus which usually results in huge points savings for an IN commander) or the Despoiler (which always has a-boats, is faster, has better lance strength and flexibility, better torpedo strength OR even better lance strength and is better in boarding actions). While still being a true 'battleship' and is not subject to the usual "nova cannon doom barrage" which is quite common when these are fielded.
Here is the grand cruiser version.
Take the exact armament from the current draft.
10/g.cruiser, 45 turn, 20cm speed, 5+ armor, 3 shields, 5 turrets.
Special rules.
cannot CTNH, tracking systems, grav prow
What this does is make it clearly a "not quite" battleship. The tau being so close to true battleship level, but unable to really put the mass into the ship to give it durability. They do benefit from a slightly better maneuverability, but the ship is too heavy to CTNH properly. You get the best of both fluffy worlds.
Remember... you need to be able to beat Gorbag in order to make this ship properly fluffly.