I have always wondered and even more so now that I want to use their rules in the new Combat Manual for my Canopian Highlanders.
They share a similar emblem scheme and they had an A+ Dragoon rating (not a feat common among Periphery commands). The only thing they don't share seems to be warriors of Gaelic descent. That might be explained by them being in the MoC for a long time.
I just want to know, are they intended to be a proper Highlander unit? Or is the name and insignia just a coincidence?