Are they any advantages to buying this DLC if you do not play as the UK or a Commonwealth nation?
So what are the advantages.
Spearhead battle plan added. This is an order which tells units to advance along a straight line without spreading out, disregarding their flanks. They will bum-rush whatever their target province is, without waiting for other units to catch up.
No, don't buy it, because Paradox needs to finally learn that releasing half-polished games with $500 worth of DLC is NOT the way to go, and learn the hard way. I'm playing Witcher 3 now, where the Blood and Wine expansion, priced at $19.99, gives you 28(!) hours of content - and that's average play length if you don't complete everything.
...Meanwhile at Paradox HQ, we get a few new talent trees and a precise attack command that should have been in the game from the start.