I'll give you my "solution" to this problem. Frequently, I like what topaz simplify does, except that it destroys too much detail. How to get the overall simplification while retaining detail?
I often use two layers. The top layer is the original image, but with increased detail and contrast and saturation, and it is partially transparent, anywhere from 30 to 89 percent opaque.
The under-layer is the topaz simplified layer. This allows me to get the simplification/posterization/colorchange, yet retain as much of the detail as needed.
I would like a "blend" of the two barns/meadows, and a sky from you hdr sequence, or from the original single image with strongly reduced highlights, to eliminate the typical distracting "hdr grunge" look. I frequently layer image variations and erase portions to achieve the kinds of blends I'm talking about here.