I said "Use other system"
I ran an MGT game (before HG) set in TNE1248 with some high Social Status characters that were aboard Cruisers and Battleships (100Kton+). Since Mongoose didn't have HG out yet, I extrapolated everything and basically told a story.
The players were gunners and I let them roll to hit and if they did hit, I described the damage without actually rolling anything. I knew where I wanted the battles to go from a story point of view.
This cinematic approach seemed to work REALLY well and the players liked it a lot. THEY felt like they were influencing the battle, but the overall outcome had been predetermined by me. The fact that they blew up one Cruiser and severely damaged another did not affect the overall outcome, but they got to be a part of the victories.
I may never use actual rolls for capital ship combat again.
Besides, with most groups, they can't even fill all the positions on one ship, let alone an entire fleet. Even as command officers, you can either roll thousands of dice to determine what happened, or just decide what happens and let the players affect the little things.
Now, having said that, I LIKE the idea of Barrages and being able to reconfigure your ship's weapons on the fly (changing barrages around), so I will definitely be incorporating that into my narrative combat system.