Mini-tournament "Time of Change"

Question for DmitriyAS: "Rusty dragons position themselves between 1 serpent and 23 wyverns, without attacking anyone." How can this be explained, and where did you learn this?
As always, I will be very grateful for your answers.

Through trial and error. It's difficult to track the pattern if it's not possible.
And in general, don't focus on this specific moment. If there's no such passivity from the Rusty Dragons, I had a backup option – separating 1 gorgon (instead of 1 serpent) and placing it next to the lizards. In this case, the Rusty Dragons attack this gorgon, which is also an option.
I usually approach each battle very flexibly because there's almost always room for improvement, and you might encounter it unexpectedly.