Easily two flags per regiment. The flags you're linking are a National Colors with decorations specific to the 16th. A regimental color, again specific to the 16th. During the civil war it was common for the ladies of the regiment, wives, girlfriends, daughters to make the regimental flag. In camp and on the march these two flags identify the headquarters. Each sub group of the,regiment the 1st, 2nd and 3rd battalions would also have their own colors and standards down to the company level with a national color and a company guidon, swallow tail flag to each company.
As they are both associated with the 16th you could display them crossed. Looking at the flags the US flag is upper left and it's staff is in front of the other flag.
Tigger