I see what you mean, excellent post. Let me rephrase a bit - it seems to me that if you're relying on players who can basically do everything without help, then you may have a style, but you don't really have much of a system. That doesn't make it wrong, or a bad approach, but it does mean your style falls to pieces without those players. And that's the contrast - Klopp, like Benitez, has much more of a system. It's not going to fall apart in the same way with a couple of players missing.
I'll disagree again
"System" in football is the set of principles of attack and defence through which your players play the game. The principles are divided into principles of attack and principles of defence. The principles of attack are - Penetration, Depth, Width, Mobility, Creativity/Improvisation, Surprise/Counterattack. The principles of defence are - Pressure, Cover, Balance, Compactness, Consolidation and Communication. Every team, coach, player and manager operates under those 12 principles, depending on their particular tactical bent. A coach/manager like Hodgson, for example, is very much a Penetration+Consolidation manager - i.e. those are the main two attack and defence principles they base their systems on. A coach like Guardiola, by contrast, emphasizes Width+Pressure. All principles SHOULD be coached and operational, but they put priority on different ones depending on who has the ball. The principles are also filtered through the four moments of the game: Attacking Possession - Transition to Defence - Defending - Transition to Attack. Add formation preferences to this, and you have a system So in other words, a "System" is made up of:
Principles of Attack
Principles of Defence
Four Moments of the Game
Formation
For Rodgers, the game has always been about Mobility and Improvisation in attack, then Pressure and Cover in defence. The other principles are there, but these are the main ones you can see in all of his teams. The problem, obviously, is that Improvisation almost 100% relies on the quality of the attackers. It doesn't mean the system falls apart when Improvisation isn't there, because the other elements remain. But it makes it harder for your system to be effective. Similarly, Klopp's principles are "Pressure" in defence and "Surprise/Counter-attack" in attack. Counter-attack requires great speed. When we don't/didn't have speed up top, the system wasn't falling apart - it just wasn't as effective (the first season is the best example of this). When we added Mane, the system didn't change, but it became much more effective. When we added Salah, though, it jumped a massive level. But again, the system doesn't change if neither of them are there - the players still play the formation, they still play the same principles, they still operate under the same four "cues" of the game. But the system remains regardless, unless Klopp makes a fundamental change to the principles in light of personnel issues. But most coaches, at all levels, don't do that. Instead, they try to recruit for the system. For Klopp, this means speed and aggression. For Rodgers, it meant high level technique and either physical or tactical strength in the attack. This is why he favours a mobile target man up front - usually a strong, tall player like Graham, Benteke, Lambert, Dembele, or Edouard. But that's because strong, mobile targets can create their own goals, through strength and height. Without that, he needs players of the technical level of Suarez or Sturridge (or Sterling to a lesser extent) who can improvise and create goals out of situations that look secure for the opposition defence.
For Klopp, the first principle is "Pressure". That's the overriding guiding principle of his whole outlook on the game. That means that players who aren't always the highest level technical players can function really well in his systems, because the first principle of the whole thing doesn't require ability on the ball - it requires physical qualities like agility and stamina and speed, and mental resilience. This means that Klopp can do better with bringing players in (lower technical standard than Rodgers demanded), and can make his system work regardless of the technical or creative ability of his players. But it comes with a price, as we know - when teams don't use the ball, don't possess it, and don't worry about getting forward to attack, Klopp's system can hit it's limit. At that point, Klopp is then looking for the same thing Rodgers was - players who can create their own goals. But that doesn't mean there is no system, or that it's "all over the place". There is no perfect system. Every system has a limit, either self-imposed, or imposed by the opposition. For Rodgers, the system was consistent throughout both his time at Liverpool, and his career in general - possess the ball, move from position, get the ball to the goalmakers and goalscorers and let them do their thing. When there were no goalmakers, though, the system didn't "fall apart", nor did it change. It just hit its limit. This is no different to Guardiola, who - if you ever saw that Sky clip with Henry - tells his players he can get them to the attacking third, but after that, it's all on them. Take all the great goalscorers away from Guardiola, and they'd still play "Tiki-Taka" (and I know he hated that phrase, but that's what we call that style now whether he likes it or not
). They just wouldn't be as effective.
For Klopp, the system is dependent more on physical qualities than technical ones. But like every other manager's system, it has limits. But when it hits those limits, the system doesn't necessarily fall apart, or cease to exist - it just needs a tweak. And that was the same for Rodgers. And any manager who isn't Harry Redknapp, for that matter