To put it simply, If you were a Lord, Earl, Baron, Prince etc you would have a Standard, which is the long often swallow tailed banner that would normally contain the owners 'badges' and moto and probably use the same colours as the owners coat of arms. These would usually accompany the unit that the lord was with. He would also have a heraldic banner. These would be squarish and contain the owners coat of arms. They would be carried by a close retainer and mark the position of the owner. So what you might have is a unit of knights with a long Standard of the highest ranking noble accompanied by several square heraldic banners of the other nobles accompanying him. Other units that owe allegiance to that particular noble might carry a flag that contains one or more of the badges that are featured on the standard. Badges might not have anything to do with the coat of arms but might be a heraldic joke, a nickname or a message in pictoral form.(the dukes of burgundy for instance have had a series of badges, knotted wood crosses, planes, flints, sparks etc all related to a herladic tit for tat). In addition to units raised by nobles you might also have units raised as militia from towns or guilds and they would carry their own banners and possibly be led by a noble from the town. Militia banners would contain the town badge and guild banners would usually contain an image of their trade etc. Hope all that helps!