I hope they aren't using custom terrains.
I'm 50/50 for custom terrains, on one hand they are beautiful, creative and great for funners.
However for leagues and especially for Intermediate type scheme studying the land, objects etc is part of the skill and strategy, just like memorizing pixel perfect dynahats and other moves. Studying how animals walk and jump, worms slide, weapons bounce etc is a very important part of the game.
I don't think they should be using custom terrains that are not standard with the game as not everyone will either have or want to use wormkit and it's simply not fair.