Get into a corner or back up against the wall (phnah phnah) - then arrange your spearmen in ranks of 3 in a protcetive screena round your other troops.
Cavalry ahve bascically no hope against ranked spears (you get a defence bonus for any ranks over 3 btw - but you might have trouble protecting them all)
Use your archers,xbows to keep the lousy horse archers at bay and just let saladdin and the horsey boys hit your spearwalla nd suffer.
Can counter attack and break saladin with your GG boys - if you kill saladin you will rout his army, just make sure your own king doesnt get snaffled.
The english troops are higher valour, morale and better equipped than the saracens - so they can take some hefty punishment - just dont let yourself get outflanked as your troops will panic and break - and then you're toasty teacakes.