Steam社区写的：
Alongside Order of Battle, we are working on the Banner Bearer feature, which will allow heroes to bring their banners to battle and have them carried by soldiers within their formation. Not only will this make battles more colourful and visually diverse, but there will also be gameplay effects for the soldiers marching under each banner.
大意就是不光士兵和NPC可以用，而且这个棋子会带有一定的游戏性，比如士气buff之类的。