I don't know too much about it. I do klnow that Chris Hughes of Sash and Saber sculpted most (if not all) of the Cowboy Wars stuff, which is probably why OG got it rather than WW.
I know that OG has used many sculptors over the years including Mssrs Hughes and Cooper along with a host of others, which is why the quality varies so much. I think the WW brand has included the work of others, but has been mainly Cooper. It's hard to tell though since the sculptors are never mentioned!