The battle proceeded, Finn was fighting through teeth and nails but he could not stand the onslaught much longer.
They were being pushed back, he wanted to retreat but he knew if he lost ground then this battle might very well be lost, he was smart enough to know that.
He could not give the command to hold the line because of his speech impairment but he did not need to speak; he was also surprised by the number of casualties.
The casualties were on the low side, everyone was fighting cautiously, it was a shocker because he thought they would be more aggressive.
It was like when the Mad Hound attacked their camp.
Despite his overwhelming strength, the casualties were on the low side. They have been fighting for close to an hour and their body was giving into exhaustion, and Finn realized that the plan was to wear them down so they would become easy pickings and it was working.