The similarity overall works, but 2 things I find visually jarring, the first thing that stood out to me very badly was the exact same cloud shape in the center of both images (Actually the shape of the clouds overall being extremely similar, but the high contrast spot in the middle was the worst) and secondly on closer look the figures being almost identical from one to the other. to have both characters in exactly the same pose in front of exactly the same clouds at distinctly separated moments in time doesn't seem quite right. But the figures probably wouldn't be so obvious if it weren't for the clouds.
This is early stage concept art and as such the emphasis is on design, feeling, mood, that kind of thing. The cloud photo plate is the same, the two figures are a copy paste, the environment is similar. When I mention continuity I don't mean a precise progression of time, I mean is there enough here that this could be a cool environment to explore in a video game or movie. Could these be landmark areas the characters might encounter?
They are part of extremely fast idea generation and not in any way intended to be works of art
Ordinarily concept art at this stage would never be released to the public. The stuff you see released has typically been cleaned up and reiterated many times, or is the end result of many other rejected designs that never see the light of day.
Most of the trees in this are a photo texture applied over a quickly blocked in area. There is one that is what I would call a 'stamp' brush of a tree silhouette (bottom left on that small hill). You can easily find them for free by typing 'tree brushes' into google. They're not good to paint with all the time and won't teach you anything, but they're nice to quickly suggest forested areas and put down an idea with some speed. You'll see a lot of concept artists using photo textures to quickly suggest what is in an area rather than, for example, laboriously paint a bunch of trees or individual houses. And that was essentially the idea with these two paintings. It's not a method I'd recommend for something more illustrative though.
Anyway, I believe I've started rambling. I hope I've helped you somewhere in there >.<