You have no hope of success against Edward's army. Your victory at Stirling Bridge was a one off. Retreat and surrender to the stronger side. You could negotiate a peaceful solution.
You've come this far. You have the dignity, hope and trust of all your men on your shoulders. Stay and fight this battle.
Although this would be a strategic move, you are no traitor to your followers. From the beginning you have fought with them side by side. Reconsider, with a thought for the honour of you and your men.
Play a card.
