I wouldn't call FO4 successful in a way they killed most of the RPG elements to cater to the casual audience. FO4 is a bad example and Bioware doesn't need to look for bad inspiration, especially from a game that copied some things from Mass Effect. As for Witcher, I hope they don't implement the Hack n Slash combat to Dragon Age. There aren't that many RPG with classic RPG combat aside from MMOs.