Perhaps before coming here again, you might know the basics of Scotland and Britain.
Britain is not England. Nor is Great Britain or the UK. GB/UK is England, Scotland, Wales and NI. Scotland and Scots ARE British. Scotland joined the UK in 1707, of its own free will.
Those army men you mention are as entitled to be on Scottish roads as Scottish soldiers, who are part of the same British army/armed forces, are entitled to be on English, Welsh and Ulster roads. Not forgetting that the lads you passed probably WERE Scottish!.
Sorry, but you don’t have a basic grasp of the UK and Scotland.
Clarification : I was reacting to the union jack flag on their vehicles.
And would rather have seen st Andrews cross on those vehicles.