The source is far too brief to tell an accurate account of the rout of the Scots at Falkirk. This is due to insufficient description of the historical terms and the strategy of both sides in the battle. Although a "schiltron" can be described as a “hedgehog” due to defensive barbs of spears working as protection from outside attack, it would be clearer to add some definition. The best way would be to compare this to a Spartan phalanx, which was a defensive unit designed to confuse the enemy strategy. While not totally accurate, as the schiltron didn’t become an offensively used tactic as well until the later Battle of Bannockburn, it works as a comparison.
The arrangements of the different Scottish units is important as well; the archers placed in the gaps allowed for some offense when being shielded from enemy attack.
Also, the knights were intimidated by the superior English numbers after they attacked, fleeing, rather than running when the English knights attacked the Scottish lines. This gave the English knights an easy target due to their speed and maneuverability.
The English longbowmen were far more experienced than the Scottish and better equipped; this allowed them to neutralize threats to their knights. While the English knights largely waited until the longbowmen dealt with the schiltrons, they did eventually proceed when the enemy ranks were thin enough to apply the brute force of the cavalry, resulting in large casualties for the Scottish amid a decisive defeat.
These combined tactics also required precise movement and discipline, so it should be noted that King Edward I’s presence on the battlefield (a rarity in these times) had order rule the day, and make the subsequent rout possible.