Songs of Syx

Songs of Syx

Warhammer Overhaul Beta v69
How to start off with zombies/gravegoard?
I have the tech and buildings built to produce zombies or grave guard. All the needed resources too. However the system tells me that I can't produce any children 0 limit because I don't have any zombies or grace guard already. How do I start it off? Is there a building or something for it?