Maybe
You're wrong, no?
Xhaka is still an asset for set pieces. He does help a lot with that with his good positioning and heading. I would say with one more midfielder next to him, he would probably take more risks in his passing and would offer more than Elneny in that case. But I think instructions are clear from Arteta, he avoids complicated passing with us, but for NT he has a bit more freedom and looks better for them.I personally would much rather see Elneny in his place. Elneny has more positive attributes than Xhaka. Is more mobile and is easier for the CBs to find when we play out of the back.
But yeah, I also thought about the possibility of Elneny there, but I don't rate him either.