Nerves

Mark, Riger, and Hunn had to account for everything. They had to plan out what would happen at night when visibility was low. They had to come up with a way to protect the cavalry from being attacked or ambushed. They had to find a counter to the light magic the angels used. They even had to account for food, supplies, and the possibility of a drawn-out battle that could last days.

What was Freya trying to do by giving him a trial like this? 

A small part of Mark's mind was trying desperately to figure out what Freya could possibly be trying to achieve by putting him in the middle of a war, while the rest of him listened and responded to Riger's words. Was Freya trying to teach Mark how to become a ruler? Or was she doing this because she knew that Mark didn't have prior experience ruling anything, and she wanted to watch him fail?

Mark had no idea.