Okay, so, admittedly not an active player (in WHITE or BLACK), but wanting to be helpful, just going to opine a bit....
Here's the fleet list (props to
@Cloak&Dagger for compiling that, by the way).
The goal here is to get as many people off Earth as possible, yes? As quickly and safely as possible?
So it makes sense to identify the best targets of those refugees.
The Macross Island is the prime choice, but the Lucrehulks seem like good short-term targets for transport as well. The 40k ships seems like good people-movers in the short-term, as do several of the Homeworld ships. Also, the Behemoth Battlecruiser.
But the trick is getting folks places?
Maybe divide up the biggest ships and designate areas, then try to evenly split the transport capabilities?
Have the various big people-moving ships get as low as they can; the Island should probably end up in lower atmosphere (but not landed), and the Battlecruiser the same, while the 40k, Homeworld, and Alienverse ships go for the lowest orbit possible.
The idea being to give the shuttles and such everyone has more time to be running more trips, rather than wasting time on the up-and-down trips to and from the ships.
I would suggest that all but 2 of the Defiants be tasked as, essentially, relay stations, using their transporters to move people from Earth to another ship; worst-case this might cut their transport rate from 175 an hour to, say, 100 an hour. But that's 1,200 people more than otherwise might get rescued. Given a day, it's almost 30,000 people. A drop in the bucket, but every drop counts.
The last 2 could be free to try and beam up "high priority" targets, or maybe go for more isolated pockets of people scattered around.
The CR90 could probably try making a few runs down and back up to the Nebulon or another ship, just cramming as many people as possible in and then offloading them. Not 100% efficient, but it's something.
Basically, the key seems like trying to divide up the "big boys" and space them evenly around the world, and then use the smaller ships to ferry them.
There's risk in putting ships down low and close, but the trade-off is more people?
I dunno, I do feel like I'm rehashing a bit, but still.
Actually, could the SC Battlecruiser safely land on the ground? If so, that would be ideal there, since it would let them donate the Medevac Dropships to help shuffle people up to ships that can't land.
Once you've evacuated people as quickly as possible, then it seems reasonable to look at trying to shuffle them to the most comfortable ships, so that the other ships can operate effectively without worrying about loads of civilians on-board.