I wish Disney the best of luck with Benioff and Weiss. Looking at the screenplay career of Benioff, I do think he is talented, some great films and fantastic Game of Thrones seasons on his name. But there is a stark difference between adaptions/remakes and new stories. The Kite Runner and Brothers (great) vs Wolverine: Origins and Stay (hot garbage) for example. My gut feeling is that Benioff is not the guy Star Wars needs right now (an exciting new storyline), especially after The Last Jedi. Not sure what Weiss' role is, I think he wrote some books before GoT but am not familiar with his material.
Rian Johnson has some great potential in my opinion, but not for a major family blockbuster trilogy. A separate film doing some entirely different (a mystery film set in the Star Wars universe or something). The way they approached the current trilogy was not that great either. Should've been Abrahams for the entire thing.