Although they have been setting up the magic array here all along, they are also aware of everything in the outside world. People are always bringing in news from the outside, indeed, having a large force simplifies many things.
Because these people relay messages, Du You doesn't have to go out to look for himself.
Similarly, Du You's undead outside have also acquired a lot of information that professionals couldn't get, so it's a matter of different focuses. In short, everything in the outside world is becoming more tense.
On this day, Du You finished drawing the last stroke, and looking at the others, he saw they were almost done as well. With the magic array completed and the power flowing, there was nothing more for them to do.
