I think the scale is ok, but I also think there is a problem with the brush opacity being inconsistent between the different sets. Also, some mountains are superimposed over others. And some rivers pass through mountains/hills, near the small lake for example.
Jungle mountains are regular mountains but with trees on them? Most fantasy maps chose to only show one geographic element at a time, probably because it's hard to draw a good looking bunch of trees on a mountain given the scale. I cannot find many mountains covered with trees at this scale but it can be done if the mountain is large enough.
For the plateau, there are a bunch of artists here that you can look at for inspiration. But personally I would recommend you to look at the work of Erwin Raisz (btw not a member of the Guild!), here for example: https://makingmaps.net/2008/04/03/map-symbols-landforms-terrain/
He does depict plenty of different geographic formations.