I've decided to upload the PSD of this matte painting! I've also cleanly layered, named, and grouped the PSD you can peruse it at will! There's so many ways to make concept art and this is just one way. The process for this one involved using only Photoshop, no 3D at all. Special shoutout to Photobash.org, whose awesome photo packs I used in making this matte painting.
-Cleanly Layered PSD
-Color-Coded layers and color key to explain each layer's use