If a surface is in good shape then it doesn't need painting, yet. With proper prep a paint job will last much longer than a single year. Most stains will also last beyond a year, even clear and semi-transparent stains. This does seem a bit too often.
Sounds like you need to do an extensive evaluation of each building to find out what a good maintenance schedule is. This is pretty simple. Write down the condition of each surface on each side of each building, take pictures for a visual record. Wait a year and take a look at each surface and write down any changes. The surfaces can be categorized; like siding, fascia boards and window trim.
I'm sure you will find that some areas need painting more often than others.
Also write down the products used. If a new paint or stain is used you can now track its longevity. All of this should have been done from the beginning.
Bottom line; I would wait a year and see what needs to be painted.