I tottaly support Dragomir - in real shieldwall You are keeping the guy in front of You busy, not fighting him - You should all the time look on enemy on Your left or right, wait for him to reveal and attack. When using normal, uncovering attacks on person in front of You to distract him, You can easly get a spear to the face.
By the way: long, two handed spears and daneaxes should blowback while thrusting. In real shieldwall warrior using a daneaxe dont have shield protection so he is stabbing the guy in shield so he can keep him on distance. I mean just soft pushback or/and stopping the attack, not knock-outing the thrusted guy. As far as I know, stabbing with daneaxe take some damage, and it is a bit ridiculous.