We dint get dressed for nuthin.
Wallace wasn't a poor commoner, he was the son of a minor nobleman, landed gentry, and knight. And there's no surviving historical evidence that Jus Primae Noctis was anything other than a fiction created by a traveling minstrel known as Blind Harry.
The kilt -- even the great kilt, the feileadh mòr -- wasn't invented until 300 years post-Wallace.
Same with the 2-handed broadsword. Invented ~300 years post-Wallace.
There was no Irish contingent at Falkirk. On either side.
And did you notice something a little conspicuous missing from the film's depiction of the Battle at Stirling bridge? Like, oh, I don't know, ... a bridge ?
The Scots were also missing their commander. Andrew de Moray was in command at Stirling, not William Wallace.
And none of Wallace's soldiers are shown as wearing chainmail. When Caesar came to Brittania in 55 and 54 BC, he and his men were wearing chainmail. So it had been known in those parts for more than a thousand years pre-Wallace.
You won't have much of an opportunity to grow an experienced army without it because without chainmail your combat experience very likely will be one and done.
Other than that, ... great film. [roll eyes]