Hopefully someone finds this useful
For those people using Vector Magic to combine images you can actually use 1 point perspective to find the right scale for everything. It's really easy, just watch this video. https://youtu.be/7u6yBDmtg48
One problem you will run into when combining images is that the originals are viewed from different angles. If you have an ocean viewed from a high angle and a mountain viewed from the front slapped together it's not going to look right. Not much you can do about that except try to find pictures with similar camera angles.
The Siege of Feldmere https://www.warlight.net/Play?PreviewMap=42171
has that problem because the houses are on a different angle. I like the map and the houses add a lot to the gameplay by adding choke points but they were made using a different method than the rest of the map. Most of the map is drawn in isometric perspective(all walls are the same height). The houses were drawn in 2 point perspective from a forward angle making them seem to pop up from the map and not be attached to the ground. Not only is the difference of angle a problem but an object in 1 or 2 point perspective can't be copy pasted without adjusting.
I made this to show what happens when you don't adjust 2 point perspective duplicates. Notice the optical illusion that happens. The two on the left and the one in the middle look like they are 3 different sizes but they are identical.
Here is the house from Feldmere with it's original horizon line. Notice that if I stay along the same lines I can shrink the house and make it work a little but the further I move left the more out of wack it becomes with the right vanishing point. More importantly it shows how scaling becomes a problem because of the large size difference in a short space.
You can get more room by spreading out the points but it is still limited and more work than it's worth.
I thought about making a map using perspective a few years ago but decided it just isn't suited for a Warlight map. Maybe as something decorative but not for an entire map. I think the best way is to make all walls the same height(isometric perspective) like you see in Huruey's Castle, Complex and Feldmere. This way you can copy paste and repurpose things without adjusting. It has a nice consistent look. It's also the method of a lot of old games like Age of Empires.
Just a quick example.
This is an abandoned map idea from a while back. It's based on the Firepro Wrestling series and uses the same method.