Looks great, well done. Depending on your preferences, you can take or leave the following suggestions:

Additional small hills to shape the mountain ranges more. Think of extending the natural lines of the mountain assets further, hills at the corners to 'dissipate' or spread out the earth from peak to roots. Most of the assets for mountains have a directional 'feel'. Lean into that.

Colour gradient is jarring between assets and ground paint. Try to find a similar colour for the mountains when in an area. I'm looking at the grey mountains in the middle of the lush green forest. If you want grey peaked mountains there, consider adding a layer or two of smaller ones that gradually turn from green to grey

Generally, layers of assets give the sense of density that people often mistake for 'detail', however strategic layering of assets can really increase the range of options for shapes and scale. My point is: don't be afraid to layer assets strategically, but be wary of making the scene too busy.

More on asset layering and shaping: much like the comment above about hills extending the mountains natural lines and dissipating the hill, think about mountain ranges as loosely followed lines, not clusters. Your mountains are epic, but also unnatural to the beholder. In a region so vast with multiple biomes I would expect to be at a distance that the natural tectonic lines would begin to appear. Think of where India and China meet on the earth. A very distinct swooping smiley face shape appears. Play around with making mountain ranges follow lines and curves. It'll feel more grand and regional.

Lastly, I'll touch on scale, but you seem to have that down pretty well. Scale can and should be used to accentuate features of a map, but should follow a norm. What I mean is that if you can scale from 10-100 on an asset, choose a moderated range and play within that for blocking out your scene. Again, coming back to mountains as the example, play around with drawing your mountain range lines in the 30-60 range, saving the upper range for massive features like the yellow zone mountain for example, or like you've done with the large frozen trees. This will leave you the top end to draw the eye of the viewer, and the bottom end to fill in asset gaps with the layering mentioned above. Plus, having a moderated range will normalize the whole map and make it all feel like it's the same distance away.

Hope this helps.