Originally Posted by Mr. Dent
I can see them not wanting to use Talia after her just being in TDKR, not wanting to use Selina because she's too big a character along with Diana. Sasha makes the most sense as she can just be Bruce's bodyguard and is a character they haven't used yet.
Still doesn't solve the fact that she's a more boring character than the others I listed. The only good thing about Sasha is using her to tie into a later Brother Eye/Max Lord JL movie