"Got it, they appear to meet all of the criteria."

Yes, as both Bill and I pointed out, your own "short term" issue that you stated meets the criteria of Non-Rental. Now the determination is:

Passive or not, based on the activity or operation. You never stated what they are doing or what sort of property this is done with. In other words, what is the business operation and how do the properties relate to that operation? Are you intending to lump them together? Are they all of the same type?