Gratitude.
Haley had drawn a copy of the pattern that Ozul had shown before, and as he made his way towards the Ashin family's manor, they began to generate as many copies as they could under strict supervision from Raven and Blaze.
As Ozul had ordered, he didn't want any alterations in the pattern while copying, so even with hundreds of people at work, it took them a while to get enough copies.
The main problem was that not every member of the Three-Eyed Strangers had taken strict secrecy oaths. Some of the oaths for outer members had a few loopholes, and as such these people couldn't be trusted with the task, as per Ozul's order.
As a result, the number of people who could be assigned to this 'simple' task was significantly reduced.