Average height of normal sage brush is 3.3 ft tall. Something to consider before you clear it. Sage brush is natural habitat for birds. This means that larger sage brush works well with chickens. They can easily get away from predators in it. Sage brush burns hot, is dirty, and produces a lot of sticky tar like soot. Even when we have range fires, the tar is left across the lava rocks.
Uses for sage brush:
Rope making, Sage brush bark after time falls away from the brush with younger bark growing under it. The dead bark is long fibers that can be soaked in water and worked into very strong rope and twine. Native Americans and early settlers often made snares for rabbits , coyotes, and fox from sage brush bark.
Sage brush of the Artemisia tridentata variety are a natural antiseptic. The plant also contains a natural pain reliever, coagulant, and inflammation reducing qualities similar to aspirin. It can be toxic to the liver and stomach if taken internally.
Sagebrush provides food and habitat for a variety of species, such as sage grouse, pronghorn antelope, gray vireo, pygmy rabbit, and mule deer.Often, sheep and cows thrive in sage brush areas.
When burned, the heavy thick smoke is well suited for smoke tanning hides. The tar and chemicals released in the burning work their way deep into the hide and seal it well.
As for how big it can get ...
No joke or trick, I've seen it myself, and will look for more pictures of large sage brush. This is common in areas with lots of water that rarely burns in wild fires. We have several giant sage brush at my grandfather's ranch in the treasure valley.