Despite the very short time for the preparation against the horde of Zombies, the Ivory Possge Gang moved pretty quickly under the leadership of Mathian which shows that he's not just someone to sit in the back and watches how the fight plays out without involving himself.
Mathian being in the frontline greatly increases the morale, especially his stern expression.
As a leader of such a big organization that housed hundreds of people, he has many responsibilities and his breaking down will spill the doom of the organization. It's the basics of becoming a leader, and Mathian seems to understand that clearly.
'I prefer him being the other type of leader, but it's fine...'
Pati shrugs his shoulders knowing that it'll be better for Mathian to be a bad leader, but then again if he's a bad leader then he wouldn't be able to amass such a number of survivors under his wings.