Think Klopp need to take a little look at what Chelsea did and put three at the back, atleast against the lower teams so we can have cover against their counters. It will free up the possibility of wingbacks to cover the flanks and use Moreno. I know Moreno isnt the best fullback, but as a wing back he can do a good job (Milners form has dropped quite a bit lately). That way we can maybe attack a bit more freely as well. Our current set up works against the better sides, but we are so vulnerable against counter attacks against the lower sides.
I would actually like to see us move to Klopp's favored (at least at Dortmund) 4-2-3-1 next season. Unfortunately, we don't really have the profile of players for this formation.
Glaringly, we are obviously missing the type of #9 you would want in this formation. Someone to play on the shoulder of the last defender and look to bring others into play. A "Torres" type of striker would be perfect. Strong, fast, technical, and deadly clinical in front of goal.
Then the three behind that striker is already set with Coutinho, Firmino, and Mane. The intelligent movement of Firmino would complement a top #9 and Coutinho and Mane could continue to play in the "half spaces" as Klopp prefers.
The midfield 2 is obviously where we would need some new players. Hendo could certainly continue playing as the DM, your typical destroyer with good to sometimes great passing. Alongside him we would need to recruit a top quality deep lying playmaker. Someone who can spread the ball around with pace and precision.
The two players who really don't fit in a "2" in the 4-2-3-1, but are ideal as the forward midfielders in a 4-3-3, would be Lallana and Wijnaldum. You could certainly play them further forward but that would likely be as 2nd choice behind the current front 3.
If Klopp wants to continue playing a high line, which I think he does, then we definitely need at least a top CB as well as better attacking fullbacks on both sides. A high line also requires a quality "sweeper keeper" which I think we have in Karius.
Karius
Ward
Clyne Matip New CB New LB
Arnold Gomez Lovren Milner/Moreno
Hendo New CM
Can Grujic?
Mane Firmino Coutinho
New Attacker Lallana Wijnaldum?
New striker
Origi
Ings?
Doesn't look a great side right now but a few really good additions could see us start on the path to a top team. Transforming the side isn't going to happen in one or even two summer windows though. Klopp needs some time to get his players in and develop them as he prefers his teams/players to play.