You might have to have a living body to control the full power of the tailed beasts. Plus obito had put chakra rods on the tailed beasts as well so maybe that is how he accomplished it.
If i remember correctly, the gedo mazo transfered the bijuu's chakra to the different jinchuriki paths. As even when the stakes were removed, the power still remained in the gedo mazo. They weren't re sealed into the edo tensei jinchuriki, i believe.
I think them being hosts when alive had a big part of the reason why they were able to use the sealed power. Think about it if this were possible then why not use the third Raikage as a tailed beast host and ect?