Zach could not honestly say that he was excited to go with Yan, but since Yan was in charge, he also couldn't say he didn't like it, so he just stayed silent while the second prince of the Empire and the military officers of Rittel discussed the plan and any necessary details.
Since Yan was on board with the idea, no others were brought up. Zach, Yan, Lahso, and Garad would be entering the territory occupied by the barbarians to wage guerilla warfare.
It was not a good plan since the barbarians wouldn't just let themselves be harassed. Yan was also a highly valuable hostage to the point where the barbarians could send one of their powerful fighters to capture him. It should be fine as long as they didn't find out his identity, though.
Instead of getting taken hostage, he would just be killed in the fight.