Nate. Any magic fleet accusations are ridiculous. Even with the changes we have proposed, The Custodian comes NOWHERE CLOSE to an Eldar battleship in agility. The changes proposed only bring the Custodian CLOSE to normal battleship levels, not there, but close.
You can talk all you want about fluff, but with hundreds of years of development and shaving 2 hits off your battleship, I in no way believe it would be unreasonable to up the forward firing flagship's manouverability. Especially because the kororvatra is a complete upgrade and redesign. Its a ship design issue, not technology, as stated before. Its just a different model car, with better technology as well. That ship is grand cruiser size, with wide drive dispersal.
You can state design intent if you want, but dont use fluff on this one. The Protector needs greater manouverability to keep up with the fleet its supposed to support. At this point, its the nimble Protectors adjusting to the advancing gunline, while the Custodian is left behind, its soft nose closing straight into the enemy. Very bad, man.
Its a ship that doesn't gel with the fleet, and you are forcing houserules on me. Its a big mistake on your part, I believe that more than any other ship model discussed.
I'm happy to hear a prow deflector is being considered. Means I may only have to houserule one thing in the fleet, and possibly Protector costs, but only after playtesting.
Let me be clear. I like a balanced fleet, with weaknesses. Kororvesh Tau have those weaknesses.
I'll be very happy if they never gain the durability or long range of other fleets. What I am proposing is simply quite rational, balanced, and fluffy character in the fleet. Magic fleet my ass. *mumbles crankily*