And if so why don't any errors pop up in-game saying your 'missing scenery blahblah.bmp'?
The map isn't using those "extra" scenery-gfx, so no error will occur.
I'm guessing it's because
MM JayBee was experimenting with the scenery on Equinox in order to find some suitable scenery. Any scenery he didn't use must've been deleted from Soldat. PW keeps in a list the scenery used on a map, regardless of whether they are currently in use or previously used.
If you select "Clear Unused Scenery," all those nonexistent scenery files will disappear from the list.