I wouldn't say a rag tag army as such, by 1314 they were quite experienced. Some 500 mounted knights led by Sir Robert Keith made the day for the Scottish army by taking out the English archers, and lets not forget that fine English army was led by the inept, Edward II.
The Templar order had been disbanded in 1312 so technically speaking if any of Keith's horse soldiers had been Templars, by 1314 they were not. At the same time Robert the Bruce who had been excommunicated from the Roman Church wanted absolution and the use of Templar soldiers would certainly hinder that, so for history they simply became Scottish soldiers and did not fight under the Templar banner. Remember the winners write the history books.
And, for the record, I'm not saying all 500 horsemen were ex Templars.
A main branch of my family is from Connel and Paisley!
Cheers, Loki