Hi Darren, there should be a Schiltron rule in the HYW supplement. Here is a variant that I am currently playtesting but which you might want to try out in your games. I should stress that this is not an official rule, just something we are testing in our games. Cheers W.
It was common for medieval phalanxes when cornered by the enemy to form into a crown or hedgehog and face in every direction. This was often the last gambit, as this meant that the phalanx would remain motionless. This is what happened for the Flemish at Roosebeke, the Scots at Cravant and the Swiss at St. Jacob-en-Birs.
Any medieval phalanx may during the movement phase form into a hedgehog. To do so, the phalanx must surrender its whole movement and have at least 4 bases remaining. Arrange the formation so that the width and depth of the unit are as equal as possible, turn the models in the flank so they face the side of the unit, and turn the models in the rear of the unit 180°.
As long as it remains in hedgehog, the unit cannot move. It has no flanks or rear, and all sides are considered as the front (so the enemy cannot claim any bonus for attacking the flank or rear of the formation).
The unit counts as a phalanx and retains its close order bonus but may not claim any depth bonus.
This close packed formation is vulnerable to shooting. So, all shooting attacks made against a Phalanx deployed in hedgehog receive a +1 modifier ‘to hit’.
The unit must spend his entire movement phase to reform into an ordinary unit and be able to move again.
As soon as the number of bases in the unit drops below 4 all hedgehog benefits are lost.