Most german tanks are a little over 10 ft hight....you can use that as a referance. Weed wackers do not multch and they will distroy any biuldings made out of modeling stuff. I have seen people dress up cinderblocks to look like houses but a weed wacker will tear up any paint you put on them.( again, don't askme how I know this)If you are going for dirt, just lay out like 40 bucks for grass killer and hose the place down. It only kills the grass for about 6 months anyway. It will kill what ever it touches but you can lay down seed in a month or so and have a new lawn as long as you water it daly...If you have a sloped area, liik out for rain washing every thing away.