Walkthrough tips, Discussion of Campaigns [Heroes 5]

As you can see, the Gunner and the Hedgehog have completed the Necropolis campaign:
So, the question is, how can I make the Night Owl jump into the portal to Ethla, even though I have 110 dragons, while the minimum required is 20?

I've tried everything, even 120, but it still won't jump into the portal. I've tried so many versions, and I even increased the number to 200, thinking it was a typo, and I upgraded them and added another 200 simple ones, but it still won't jump.