Now that I've seen the Sing Off China clips (which I didn't know existed), I'm wondering about the re-dos. Surely those were because the actual song arrangements were done by people on the US version, and thus they were intellectual property that the franchise could re-use? Thus, it's not REALLY Freemen's fault that they were given the arrangements to do... I'm guessing they weren't alone in that sense.
Mind you, the a cappella arrangements of C-pop tunes were great, as much as I didn't understand what was being sung. I've got some great covers of anime tunes sung by Japanese a cappella groups in my collection. That, and Rag Fair is awesome.