The maids are pretty weak overall, I think that came up in the first season. The six of them and Sebas are supposed to work in concert with each other to defend a portion of Nazarick. That's why he took Nabe out with him to play adventurer. The maids are believable in the context of the recon they did earlier (where nearly everyone else is much weaker).

It's the individual floor guardians that are true beasts, meant to handle raiding parties with the assistance of the players that are logged in at that moment.

They've been discovering over this season that while the lizards and Brain and most adventurers might be considered weak as well, there are individuals out there that begin to approach the level of player-created NPCs. Or people like the Princess who possess a level of intellect that compares to super-powered organizations like Nazarick.

We don't really know how they figured out the location of the bases...but we do know how the princess did it. If it took her about a half-hour to crack one of the Eight Fingers memos, but it seems to have taken Nazarick a few days to find them all...well...the people of this world aren't quite as weak as initially assumed.

Ainz has been trying to break his floor guardians arrogance about the rest of the world, and it's finally starting to stick.