Obi-Wan is a key character in ROTS and must be captured in a statuesque way, like Ani has been made. As I said the best way to make a ROTS Obi-Wan PF is the image I posted before IMO as he looks concerned, calm and ready to fight at the same time. I personally don't like the pose where he fights Grievous at all for a PF.
Definitely, the pose you posted embodies Obi-Wan, just needs some subtle arm positioning to breathe a little more life into it. Statuesque poses like the promo you posted are great for statues, but because PF uses real fabrics, something that causes better flow to the costume and all for a more dynamic look would be great. As I said, Anakin is pretty basic in pose, but there is a certain life within it that I'd want in an Obi-Wan as well.