Was Edward II crucial to England's victory at Battle of Falkirk?
Let’s work this out in a step by step way to be sure we have the right answer.
no
The Battle of Falkirk was a battle between England and the Scots.

King Edward I led English forces to victory against William Wallace at the Battle of Falkirk.

The Battle of Falkirk took place in 1298.

Edward II was born in 1284 and his first campaign with his father against Scotland happened in 1300.

Edward II was knighted in 1306.

.

So, the final answer is no