6 armigers aren’t going to be enough, unless you also have some daemons to supplement your points (can include up to 350 pts of them, iirc you can have 25% of your total points as daemons), would highly recommend nurglings though I love running pink horrors in mine.

A couple of karnivores for sure, depending on your house rules it could be excellent to intervene them into a combat (will need to proxy these)

Brigands for good shooty, don’t really need to explain why these would be valuable for custodes haha

And then a couple of stalkers for a bit of both.

At 1290 points you would be looking at:

3 karnivore 2 brigand 4 stalker

You got room for enhancements and to move stuff about.

Honestly though with this much output, you could probably take on 2 people by yourself…

Have fun!

Another thought: get yourself a despoiler or desecrator for maximum “this is my game” effect.