1Xx_ASH_xX1
Replacements weren't nessecary, not really.
It's been a few years since V, Uzi, and N killed Cyn and J, and now the whole population on Copper 9 can live peacefully.
But of course, it doesn't last forever.
A landing pod was spotted on November 14th of 3074, but nothing was suspected then, most assumed it was a ship that humans used to get here, until four days later on November 18th, that workers started going missing.
Of course, they all thought it was the disassembly drones, but even Uzi comfirmed she was always with them, so there was no way that they could kill, plus they used a source of oil they found from the (already) dead bodies they found all around.
But it was one day N, V and Uzi unintentionally found the issue, four disassembly drones sent from Earth.