I know it isn't a critical thing to do, but I do agree that eventually having just one file for those core elements is best so it's easier to keep track. I wasn't sure which value was the one being used and they weren't identical.
I think understand what you mean, but some of them listed say, TERRAIN_PLAINS twice. I would have just thought that if you wanted the bonus placed on a Feature, you would just list the Feature, and if you want it on the raw Terrain AND/OR Feature, you would list them both, without listing Terrain twice.