Maybe its the other way around, maybe you haven't seen enough of Yaya
To be honest,
his time at Barcelona made people get a false impression of him, Yaya is not and was never before Barcelona a defensive midfielder, he was always a center midfielder, a box to box midfielder who likes to charge forward, and at the same time is quite good technically, better than he's given credit for. He's played that role both for Monaco and his NT. Mancini recognizes that, which is why he plays him in a more advanced AM position.