Yeh it will be interesting to see where Oxlade-Chamberlain ends up playing maybe in the kind of role Sterling enjoyed late on in 13/14.
At Dortmund, Klopp did have 1 proper winger in his side usually with either Kuba on the right or Grosskreutz on the left.
It seems he wants to always have 2 goalscorers and 3 providers on the pitch, regardless of system. At Dortmund that was Lewa & Reus being provided by Gundogan, Kagawa & Kuba. There were various other players added to, but usually you can identify the 2 scorers and 3 providers regardless of who played.
In our system, those 2 scorers are Salah & Mane. The providers are Firmino, Coutinho & Gini. Here is where it gets tricky though. With Salah & Mane functioning better attacking space that Firmino leaves rather than playing up against the center backs themselves directly, we end up with a narrow front 6 and the width coming almost exclusively from the full backs.
Therefore in the current 4-3-3 Chamberlain seems suited to one of the dual #8 positions, likely the 8/10 hybrid one given his lack of tactical nous compared the likes of Sahin & Gundogan. Whereas in a 4-2-3-1 he would seem more suited to the Kuba role, which is where we saw him at the weekend trying to be a provider to Solanke.
It will be interesting to see where Klopp goes from here. The 4-3-3 shares the four responsibilities of your central midfield (protect defence, link play, create, support attack) between 3 rather than two which means we don't need a pure #6 like Bender and a perfect #8 linking play like Gundogan. Gini seems suited to the 4-3-3 more than 4-2-3-1. Gini makes great late runs to support the attack and gets amongst the goals nicely. Also chips in with almost 10 assists in the league last season. Tactically he is good at plugging the gaps that Can & Henderson leave who are more inclined to move out of position towards threats than sit and protect the defence. Linking play is where he is weakest of the four tasks - which all Klopp's #8's tended to be Elite at. However, Lallana (and Chamberlain) put up elite level numbers at this task. You also have Coutinho, Keita and Lemar was targeted. Therefore we can likely play 4-3-3 without a pure #6 - or "proper DM" as we say on here with the 8s sharing the load of protecting the defence.
Then again, Solanke & Origi seem perfect highly mobile target men for a 4-2-3-1. Ox or Lemar (assuming Coutinho leaves) would be the one traditional winger. Firmino or Lallana are the central playmaker. Salah or Mane are the goalscoring wide player. Keita is the perfect #8 for the system. However, we lack the #6 to play that system now and we haven't looked like targeting one. Also I am not sure where that would leave Gini - which as one of his big signings would be an interesting situation.
I therefore wonder if we will see us using both systems in the future depending on player availability &/or opposition. That would mean needing to replace Can with a proper #6.