TFA alone may have (almost deliberately) lost in originality to the PT.
Keep in mind that originality is not inherently a good thing. Confusing and bad originality (as seen in the PT) is meaningless in my opinion, no matter how original it was.
The PT had lots of good fresh new concepts (clones, the council, new worlds, the Sith, Dooku, …). Some of them were badly executed (Jar-jar, the Trade Federation, Jango Fett, …), but GL could’ve improved them if advised by good writers like Kasdan.
Especially since we have already six episodes behind, to me originality is just as important as execution: honestly, I can hardly watch TFA’s second half about the SKB, just like with the PT, even though TFA is mostly well directed.
I don’t think George would have ever allowed anyone else to write his films again. He (for some reason) felt the need to write all three of the prequels without assistance, and I believe he would have done the same had he made the sequels.