The Climax Draws Near...

Tyr was on the run, he was being chased and he knew he was in no condition for a fight. 

At least not now, the illusion of an army would be debunked if they caught sight of him and this would defeat the purpose of his assignment.

The fact that his action had somehow weakened the main army as they split their forces to confront this perceived danger but in reality, it was just Tyr destroying their camp.

Tyr maneuvered around the terrain and tried to mislead them by firing burning arrows in the opposite direction or intentionally leaving trails to derail them.

Tyr had taken extra measures to conceal his track, and eventually, the men stopped chasing him after a while because it was a wild goose chase and they might be running right into a trap.

Tyr was surprised Sturla or Sighvatur did not lead them but it also made him question where they were.