agree. there's a lot to improve, and you're mentioning one of these aspects.
The quicker way of course is to make everything work with painted masks, but there's not much interesting challenge in that (for me), other than that it's a whole lot of work. As you can see from Dune's excellent renders, the manual technique can bear pretty results.
I'm interested in making a procedural farmland, but I wonder why I'm so stupid to even try in the first place ;-)
I remember that a long while ago, JimB made an awesome but very short animation with the camera flying down, through clouds, towards a farmland-like 3D surface, which he derived from a high resolution aerial photo through a pretty work-intensive process. The visual impression was fantastic, though.
Anyway, I'm drifting. I'll try to make something procedural, that is acceptable for high altitude shots.
Cheers,
Frank