Wow, this looks awesome.
I'm definitely leaning towards the Dehner-Mitchell-theory... Because I think that Cumberbatch's character needs to have some connection with Kirk to make a confrontation meaningful. Of course, they could have changed things around that Kirk and Mitchell both fell in love with Carol Marcus and Mitchell now returns to take his revenge on Kirk for "losing". The Dehner character was very weak in WNMHGB, after all, so I wouldn't mind a change here. *g*
"And so, shall we begin?" - Yesssssssss!!!
It's possible Eve plays Carol Marcus, but with a twist. Instead of Dr. Dehner teaming up with Mitchell, it's Carol Marcus that does making it very personal for Kirk.