[Micah]

If you want to see if a unit is PD or not while you're watching a replay you can click on the units. "Real" units will have say "Home Garrison [Province]" near the top. Occasionally the province name will be blank for some reason, but the home garrison will always be there. PD troops do not have this tag. Commanders don't seem to have the tag, but they do have different names...plus most real commanders won't be anywhere near the center of the battlefield where the PD deploys.