England-you needd to remember two things about this faction: never use 2handers, and rely on your archers, as they are awsome!
Offensive army:
For infantry: 4 Heavy Infantry is ideal. More means expenditure.
2 Spearmen, just in case of enemy cavalry. They should be Mercs, as the english pretty much s.uck at this chapter.
4 Longbowmen units. Use their stakes no matter if you charge the enemy.
For Cavalry: 4 English Knights is the ideal number. But, they will drain the economy, and I recommend using them in extreme cases. Mailed Knights are just as good for flanking.
For artillery: Some catapults work wonders. 4 units means 8 shots at every 30 secs or so. And they are intimidating.
So, it`s not even a full stack, but it is quite effective if you know how to use it.
Offensive tactics: It depends mainly on one thing: if you have turned your battle timer on/off.
If you don`t have time, the zerg rush tactic is just as good.
If you have time, you shoul try to flank the enemy, or at least, not to charge head on when the enemy took position on a hill. When the armies close, rush a part, but not all your cavalry in the enemy archers. Make sure they don't ruin each other's charge. After the initial hit, when the enemy retreats his archers, you do the same with your cavalry. It will come a big infantr clash, and if your infantry needs help, or you just want to minimise the loses, charge the same cavalry that dispersed the archers in the back of the enemy infantry. It shouldn't take long before the infantry will rout-big big big chain reaction. Have the cavalry take as many prisoners as posible-it would help experience them. Now, as I mentioned before, only a part of your cavalry force would fight the archers and the infantry, the rest should take on the enemy cavalry [who is usualy 1-3 unit max] and the enemy artillery.
If you understood what I meant, and you wanna hear some strategies for a deffensive army, post, and I will continue

.Best of luck!