It depends very much on the type of players you have in those positions. Not every diamond is the same.
In the pressing phase, it would be less of a problem than when you have to drop deeper (mostly to defend in a flatter 4-4-2, or some sort of a 4-3-3). Even if it is a difference whether the tip of the diamond is a Wirtz (current version of Wirtz) type of player or a Firmino type of player. There could be more differences.
Different versions of a diamond structure (not very often in football anyway) had different players dropping; Zidane for example could drop deeper from the single #10 role alongside the single #6. But that was also at a time when teams weren’t as compact and the game was more individualistic. The Real sides he took part in aren’t the best example tactical/balance wise. Plus, it’s bloody Zidane. In Milan’s diamond, obviously Kaka (a totally different player to the ones mentioned so far) wouldn’t drop alongside Pirlo, so that’s a big difference. Already by Athens, they were back to a more compact 4-4-2 (Gattuso and Seedorf narrowly on the sides, Kaka as a second striker). A bit like the Atletico 4-4-2’s with proper midfielders on narrow sides and a difference maker in Griezmann between the lines.
One of the two strikers (mostly the one who is more mobile) could drop to one of the sides to defend, pushing one of the #8’s more alongside the #6 to create a double-pivot shape.
I wouldn’t really see Wirtz (especially current Wirtz) dropping from the single #10 role close to our #6. So you would probably have to “hide” (like we already try to cheat the game with the way we use Salah) him narrowly from one of the sides.
Mourinho attempted a diamond shape near the end of his first era at Chelsea, that’s the time when he tried to bring the best out of a deep controller (Makelele or Mikel), a physical box-to-box beast (Essien), a goalscoring #8 in Lampard and Ballack at #10. It wasn’t great and it didn’t last long.
In our 13/14 season, during the season (and obviously Suarez and Sturridge forcing us to find a way to have them together up top, even if we had the odd game when one of them defended the side more, like I said above), we evolved into a diamond shape. Also didn’t last long.
What Klopp was talking about in the #10 role is that in his football, the single #10 role is defensively the hardest one. When he came, he immediately pushed Coutinho to the left half space and in the #10 role we initially had Lallana, but then is slowly became Bobby’s position (which then morphed into our 4-3-3 with a false #9, not too dissimilar to a diamond shape, but still different).
It’s connected to his phrase that good counter-pressing overall beats a single #10 playmaker.
The diamond shape is rare enough in the game and what I found from my memory is that even when it worked, it didn’t last very long.
For me, changing to a diamond with so many players who didn’t have a good pre-season, when the general understanding between them isn’t great, is more dangerous than potentially good.
I would rather stick to our little shape differences of a principal formation (whether it’s a 2-1 or 1-2 midfield, whether we build with 3 at the back or with our CB’s, etc.) and pick individuals on merit, not just stick the best reputation (or better to say potential?) players in a diamond shape and what, force it until it works (and if it works)?
Right now we are not compact and together enough for any type of formation, we have to work on phases of play. How do we act when we build from the back, how do we act when we press (or a mid-block), how do we act in transitions (especially defensive), how do we act in set-pieces (both defending and attacking).
