Texture painting with GLSL and scaling problems

So I saw the tutorial on how to texture paint using a stencil (http://wiki.blender.org/index.php/Doc:Tutorials/Game_Engine/YoFrankie/GLSL_Texturing) and figured it’d be good for landscape as a good first try, but I’m running into a problem.

What I do may not be the best method to do this, in which case please let me know so I can unlearn it before it really sets in, but for large landscapes that will be using one texture, I’ve basically gotten the mesh subdivided as much as I want, then I unwrap it onto a reasonably sized image, then scale the unwrapped mesh several times, otherwise the entire countryside look like one stretched out image. The tiling effect is noticeable from a bird’s eye perspective, but I figure if the player avatar is small, it won’t stick out like a sore thumb.

So for one texture, this has worked great for me, but when I try to texture paint with, say, dirt + stencil + grass channels, I run into a problem. Since the mesh is unwrapped for all channels at once (I’m just stabbing in the dark here, I may be way off), if I scale my unwrapped mesh several times larger like I normally do, it scales it that much on the stencil as well, which means that when I paint any of the 3rd channel’s texture, the effect gets tiled all over the landscape as well, which I don’t want.

I believe this could be remedied if I could somehow unwrap the mesh separately for the stencil so that the stencil keeps a 1:1 ratio between it and the overall map, yet at the same time, be able to use that same unwrapped mesh scaled 10:1 for the grass and rocky textures so that I can paint directly into the 3d view.

Does that make sense? If so, does anyone happen to know how I’d go about that? Any help, as always, is much appreciated as I learn.