In my opinion, Sissoko would need to be way more disciplined to play in a Klopp system in what is currently Hendo's role. Hendo is playing on the right of Fabinho who is the deepest of the 3. Klopp would enjoy Sissoko's work rate and driving the ball forward but he wouldn't tolerate Sissoko getting in Trent's way and filling the space that Salah so well exploits. He definitely wouldn't tolerate Sissoko leaving Fabinho exposed at the back as much as he does Winks.
I know it was only Bulgaria, but I thought Hendo helped Winks have a fantastic game. He never left him exposed and worked with him the entire game. He was constantly pulling players around and opening up gaps for Winks to thread balls into. He was also offering for one-twos. For me, Hendo sort of showed how you can be all action but still be very disciplined, and Sissoko could learn a lot from him. In reality, so could Ndombele on the left of Winks who isn't owning his midfield area or getting tight with Winks defensively.
For me, this all comes down to having a fully fit Dele and finally getting access to Lo Celso. The more talented, intelligent, hard working players we put together in that midfield area the more it will come together.