"The song is pretty accurate in telling the true story of one of Scotland's great heroes,"

Montrose is most famous for changing sides (ie he was originally a Covenanting general who switched back to the royalist cause at least partly for personal reasons) and invading Scotland several times. Firstly with English troops, then with a mixture of Irish troops and disaffected MacDonalds,then eventually with Scandinavian troops. Only his second attempt had any success but his string of victories took place whilst the main Scottish government army was out of the country occupying northern England. Montrose had once occupied Aberdeen as a Covenanting general. The city was fundametally royalist. Yet when he reoccupied it now as a Royalist general he let his Irish troops run amok for three days in an orgy of slaughter. During the same campaign the MacDonald bards boasted about killing 900 Campbells in Argyll without a sword being lifted in defence. It is easy to think about the romantic idea of the Campbell chief fleeing in his boat down the loch escaping from Montrose's allies - but who remembers the hundreds of ordinary Campbell non-combatants butchered in cold blood. Admittedly Montrose wasn't invovled in the Argyll atrocities himself but several of Montrose's own victories were marked by butchery in the aftermath of the battle. He had little active support within mainland Scotland and when the returning Scottish army caught up with him at Selkirk he made a pig's ear of it and fled Philiphaugh leaving many of the Irish (both troops and camp followers) to be slughtered on the spot by a vengeful Scottish government army. I think anyone really studying their history would be hard pressed to truly think of Montrose as one of Scotland's great heroes. He came to be despised by many during his own lifetime; was then glorified by what itself became an oppressive and unpopular Restoration regime within Scotland; then was glamourised by later romantic writers like Scott. Great national heroes tend to be involved in great national struggles. Hence the likes of Wallace, Bruce and Sir James Douglas etc can easily be dsecribed as great national heroes. I don't think any of the generals involved in the butchery of Scotland's civil wars in the 17thC could really be described as great heroes.