Admiral Raddus died during the battle of Scarif. The ship in TLJ is merely named after him.

I couldn’t find the name of the admiral in charge during the New Republic, so I assume they haven’t come up with one. If anyone knows of an admiral who was name-dropped, say, in the Resistance show, I would consider using it, though it may be best to avoid further name drops as it could imply that we will see such a character later.

I feel like the fleet massing around Hosnian Prime in response to the Starkiller threat would lampshade a tactical blunder too egregious even for the New Republic, so it’s probably best to leave that unsaid.

What about this:

“General, the Senate has voted to mobilize the fleet! They hope to launch within the hour.”
“They haven’t got a chance.”

This is pretty similar to what we already have, which I think works. With the First Order update stating that the weapon will be charged in fifty minutes, this allows the stakes to be about whether they manage to launch any ships from Hosnian Prime before it is destroyed. Leia responds to this hope of an early launch with the weary cynicism that probably led her to form the Resistance in the first place.