I had a bit of a different idea in my mind's eye about the Braha'tok personally. As it is rated a "gunship" I associated that with gunboats from the age of sail: Small short ranged boats with great maneuverability which were very fragile but loaded with only a few very large guns. They were mostly used in defensive roles, not being suited to long sea voyages, or by a desperate force that had little choice but to take a small vessel and put the biggest guns they could fit on it.
With this interpretation, I kind of thought of the Braha'tok as a similar vessel for the rebels. A small, relatively fragile ship that is significantly overgunned for her size, her purpose not being to hold the line, but rather to inflict as much damage on the enemy as possible in the shortest time possible. I think it would fit into the rebel fleet better that way, with their fighter defense being handled mostly by their individually superior shielded fighters. If this were the case, the Braha'tok would be a ship fitting in with the rebel acceptance that they couldn't challenge the imperial fleet in a stand up fight, but the ship would instead be used to, in a way, take as many of the Imps down with them as possible, or perhaps even take on a ship larger than itself with a few lucky shots in the opening volleys. This would also fit in somewhat with the way the Dornean Navy (the creators of the Braha'tok) has been portrayed in the novels. A notable quote which may support this:
A'baht: "Whatever waits for us, whether princess or dragon, we are called to embrace it. I am mindful of a Dornean war prayer I heard my own mother offer—'I pray that my son does not die today. But if he should die, I pray that he dies well. But most of all, I pray that if he lives, it will not be dishonor which preserves him.'"
Anyways, that's just my interpretation. Feel free to do with it what you will.