I think this shot could have been improved during capture if the camera were angled a little more to the left. The reason I say this is that your subjects are walking to the left... it is not always the case that your primary focal objects should be oriented in the center of the frame. If you had aimed your camera more to the left, the audience would be able to get a greater sense of the landscape that your subjects are walking towards. In other words, I believe this should would have been more powerful if you had oriented the people closer to the right of the frame, and provided a slightly larger view of the land on the left side. If you take a similar shot in the future, I would suggest you try taking a number of frames in this manner then decide if it is more effective or less effective than keeping your focal objects directly in the center.
Additionally, your photo could use some local contrast enhancement (use a high radius, low amount unsharp mask in photoshop (or equivalent) or increase clarity in lightroom). Slightly raising the black point might help as well... I think the photo is good, but as far as easily correctable post-processing goes, it needs more contrast.