An oddity

[Brian Rose]

HM Royal Marines is testing a streaming channel on YouTube. A number of clips featuring the various bands shown 24/7. The clips tend to alternate between indoor and outside performances.
One of the outdoor performances is the RM 350th anniversary celebration. It features the massed bands of the Royal Netherlands Marines, the U.S. Marines Europe and all of the RM bands. The massed bands have the RM in the center and the visiting Marines on either side. One can see a troop of RM along the rear of the parade ground. As the celebration nears it's close, the troop in the rear breaks into two companies (closest term) and moves to front flanking the bands on either side.
One of the RM companies appears to be commanded by an officer of 2 Scots. Full RRS uniform with a white hackle. It seemed really odd to see that. I know services often have "exchange" personnel but it seems highly unusual to have one in a command position especially at a anniversary celebration.
I'll admit my military knowledge is secondary and the traditions of British miltary even more so. I've been unable to find this celebration as a complete video. The RM are only showing parts of this performance at a time so it's hard to get full context. I'll welcome other knowledge or delete this if it's not appropriate.