This was my first-time using World Machine however I was familiar with nodes from blender which made this program far less intimidating, I can now produce detailed landscapes relatively quickly.
I chose World Machine over World Creator as it was used most by the creatives that I investigated.
This video shows me creating a landscape within World Machine:
Within an empty UE4 level I tested the smart material and foliage to see how well it worked together in uniform with the spawners. The pictures below show the testing.