I’m proud of my Scottish heritage, but the Spanish tercios, German landsknechts, Swiss pikemen, or any other heavy infantry or combined arms force of the period would have swept them off the battlefield. The Scots were perfectly fine irregular light infantry. They were effective on their own terrain and for raiding and skirmishing. The Scots also had a warrior culture that produced splendid regular soldiers once they came in numbers into the British army. But light infantry is light infantry. It played an important role in difficult terrain that impeded heavier formations and could be important as auxiliary troops for heavier regular armies. In main force engagements, however, the Scots were one trick ponies. Like so many other “barbarian” armies over the centuries, they relied on a wild charge to break an opponent’s formation, and if that failed, they were overmatched.
The wild charge by the claymore-waving Scottish Jacobites at Culloden in 1746 actually took some of the government troops down, but the muskets with bayonets and artillery of the government force eventually won the day.