It's really not though. Here's why:
Arteta and Klopp showed progress and you could see their fingerprint on their teams performances on the pitch.
With ETH it's the opposite.
Here's the hard stats for Klopp, Arteta and ETH for their first seasons in the PL (For Klopp and Arteta I've added their first seasons and their first 2 full seasons dsince they both started mid season):
Klopp:
1st season (started 8/10 2015 - 30 games in the PL)
1,60 points per game (under performance by 0,1 points per game)
+ 0,5 goal difference per game (over performance by 0,03 gd/game)
2nd season (Full season)
2,0 points per game (over performance by 0,14 points per game)
+ 0,95 goal difference per game (over performance by 0,34 gd/game)
3rd season
1,95 points per game (under performance by 0,12 points per game)
+ 1,21 goal difference per game (over performance by 0,42 gd/game)
Arteta:
1st season (Started 22/12 2019 - 20 games in the PL)
1,65 points per game (over performance by 0,33 points per game)
+ 0,55 goal difference per game (over performance by 0,75 gd/game)
2nd season
1,61 points per game (over performance by 0,23 points per game)
+ 0,42 goal difference per game (over performance by 0,18 gd/game)
3rd season
1,81 points per game (over performance by 0,33 points per game)
+ 0,34 goal difference per game (under performance by 0,05 gd/game)
ETH:
1st season
1,97 points per game (over performance by 0,19 points per game)
+ 0,39 goal difference per game (under performance by 0,18 gd/game)
2nd season
1,58 points per game (under performance by 0,41 points per game)
- 0,03 goal difference per game (over performance by 0,35 gd/game)
So you see progress with the first two and the opposite with ETH.
It gets even more interesting when we do the same with the underlying stats instead (from understat.com). In fact it gets really ugly:
Klopp (notice the almost linear improvement from season to season) :
1st season (started 8/10 2015 - 30 games in the PL)
1,70 expected points per game
+ 0,47 expected goal difference per game
2nd season
1,84 expected points per game
+ 0,61 expected goal difference per game
3rd season
2,09 expected points per game
+ 0,79 expected goal difference per game
Arteta (notice the almoxt linear improvement from season to season)
1st season (Started 22/12 2019 - 20 games in the PL)
1,32 expected points per game
- 0,20 expected goal difference per game
2nd season
1,55 expected points per game
+ 0,24 expected goal difference per game
3rd season
1,70 expected points per game
+ 0,39 expected goal difference per game
And then we have ETH - Notice the almost vertical drop from the first season to the second season:
1st season
1,74 expected points per game
+ 0,57 expected goal difference per game
2nd season
1,17 expected points per game
- 0,38 expected goal difference per game
The numbers in that post is meaningless because they don't show the trajectories the 3 managers had in their starting years at the respective clubs.
A graphical presentation of the results and play would be something like this:
Klopp: /
Arteta: /
ETH: \
It should be a stick to beat ETH with if anything. A big one.
Do you still want to find out where ETH's taking us next season?