Nice figures, nice terrain, nice game write-up. My Goblin horde always gets slaughtered… Always, every game, over the last 25+ years.
I would recommend visiting your local fabric stores. They always seem to have some fabric pattern for a good underground ground cloth. I found this mottled style, around 20 years ago, in my local JoAnne's Fabric Store. Here is another shot, showing it closer up.
Fabric ground cloths work exceptionally well: wash & dry to clean, and revitalize; ironing is optional. I try to go with a cotton-polyester blend, as pure cotton is too hard to keep wrinkle-free. My wife owns a Serger sewing machine, so I finish the edges of the ground cloths with that, to avoid fraying.
I've found patterns that work for various terrain types, including swamps, concrete roadways, grassy terrain, and more. I put plastic swamp plants on top of the odd oval shapes for swamps; I put cake decorator trees on top of wooded patterns of cloth, to mark out woods on the tabletop. These two techniques are not diorama-like, at all, but they are wholly functional, and they give us hard definitions of where the terrain changes occur, making it easier to play.
My wife makes quilts, so I had her combine a gray concrete-like fabric pattern with a mottled green, grass-like pattern, to make a ground cloth for my 54mm Army Men games: it appears as square city blocks, with concrete roadways crisscrossing it; I just place ruins and building sections atop it, and game. I love using fabric ground cloths… Cheers!
