Longbows -vs- Mongols

[Von Nanega]

My game is a English migration to the Holy lands has been war from the start. BUT,,, my armies, with six longbows type units with some spearmen and armoured swordsmen and a couple of Templar Knights has been destroying one Mongol army but getting wrecked in the process. It really sucks having to retrain after every major battle. These are open field battles. I would like some advice on how to reorganize using the English to get better kill ratios.