I agree with Blodrast completily: set-up far away from them, have them march towards you and pepper them with arrows. The problem is that II have a large shield and are not particulary impressed by ranged weapons, so you need to get behind their back. That's why I recommend horse archers, preferebly mounted crosbowmen. If you can pin them and get javelin troops in their back, that's great, but javelins do require some skill.
Chivalric men-at-arms probably work better than sergeants, but they are armoured and do NOT have armour piercing. Use them in a thin formation to wrap around the enemy.

Lastly: you are playing the Danes and you don't use Vikings? Standard Vikings are some of the best early infantry and they are available real early. And I won't mention the VI Viking units...