Whatever works for you is good, but IMHO that's backwards Michael. Normally, bases seem to work best on top of the mesh scenery in the Scenery Library window. What you are doing can work sometimes I guess, but I've experienced no-show display problems trying it that way.
Also confusing is that the priority number in the Scenery Library window does not translate to the [Area. 0xx number] in the scenery.cfg file text. In fact everything in the scenery.cfg file is the exact opposite of what you see in the Scenery Library window. What you see on top of the list in the Scenery Library window is at the bottom of the list in the scenery.cfg file, and vice versa. So the area that is at the bottom of the scenery.cfg list - let's say it's [Area.036] - will show up on top of the list and as priority 1 in the Scenery Library window. If you change an area number in the scenery.cfg list, it will move the scenery area to a different priority position in the Scenery Library hierarchy.