I was wondering when someone wold get around to this! I suspect there's significant overlap between Aurora and the SB/SV/TLA community. AFAIK, Nemesis would probably displace a few hundred million Aurora tons, so you're off by two orders of magnitudes, but that is to be expected. Where are her attack drones and sensor platforms though?
It was one in the morning and I completely forgot about the drones. . . oops. I skipped the ground forces too.
I think I'm at roughly the right size from the perspective of a Nemesis like ship in Aurora; like I said, crew complement, build duration, and weapon numbers match what Prox had. That said, if Nemesis is the same aspect ratio and density as an Iowa class battleship, she should be close to 800 million tons. . . .
Aurora weapons don't get big enough. . . those impactors are tiny and would barely scratch the paint on an equivtech warship. Ditto for the displacement engine (which is just an advanced spinal mount laser).
I also looked into making her self-sufficient in maintenance, but even at max tech a 5000 ton module can only support 6250 tons of warship.
On a related note, the Swarm are obviously Naiads, while the Precursors are all the remains of the Lost after a few centuries of mental degeneration. The Rakhas are all that Red One left of the Tribune civilization. . . .