In this small example, I've separated them into even more sizes, adding an extra, even larger, fifth line.

Note a small detail: in topic 2, among the standard-size trees, there are some smaller trees. Compared to the others, where only the standard size is present, it gives a more "organic" and realistic appearance, at least to me.

Trees behind and in front of the hills also contribute to a more harmonious view.

To add more depth to the image, I suggest considering establishing 3 or 4 regions in the image (at least I usually do this) where the icons change size, each time a little larger.

To avoid getting lost, I usually leave an example of the size outside the map as a reference if I need to go back to work on a previous area.

On the other hand, if you don't post either, we can't give you any useful advice to improve them further.

In my case, I can only help with the visual aesthetics and proportions within the frame. I know very little about operating the software, lol.

Where are the compass roses for dogs and cats? 🙄

Some Cartouche options for the ("empty") corners outside the Hex Center could also be a good addition to the style.