An interesting point. Not only about Sampaoli, but in general.
Some coaches are lone wolves and they don't need assistant managers, more or less, all success is because of them.
But in some cases, it is a about a coach-assistant duo.
For example, from our history, I don't know if our fans remember, but when Laporta-Rijkaard came in a summer 2003', Rijkaard was our coach and his assistant was a Dutch coach Henk Ten Cate.
They worked together at Barca for 3 seasons:
2003/04
2004/05
2005/06
In the first season we went from a 10th place to a 10 games winning streak in the 2nd part of a season, finishing 2nd behind Valencia and almost winning a title in a spectacular twist.
In the 2nd season, we won La liga after 6 years.
In the 3rd year, we won La Liga again plus a CL, our 2nd one in a 100 year's history.
In those first 3 seasons, Barca played the best football in the world back then (especially in the 2nd and the 3rd season).
But after a summer of 2006, when Ten Cate left, our team was never the same.
With Ten Cate, in those 3 years, we played like Goats for 2 and a half season and we were poor only in the first 6 Months when they came to our club.
When Ten Cate left, we had 2 poor seasons with Rijkaard (2006/07 and 2007/08).
We didn't lose any important player except Larsson (but we got young Messi). It seemed after a summer of 2006 that we just lost some tactical depth and something was just different and weaker in our overall game.
Back then I used to think that it was only because our team lost motivation after winning a CL, but who knows how huge impact Ten Cate had on a tactical part of our game (or on tactical changes and ideas during the game, when we were losing, when we needed some tricks etc).
Ten Cate went to Ajax in 2006/07, finishing 2nd behind Psv, with the same number of points but 1 goal weaker goal difference.
In the next season, Ten Cate was hired by Chelsea as an assistant for their coach Avram Grant.
Coincidence or not, a team led by Grant and with Ten Cate as an assistant reached a CL final in 2007/08 and Chelsea lost to Man Utd when John Terry (slipped and) missed a match-point penalty in a penalty shootout.
Grant and Ten Cate were sacked later.
My post in not necessarily about Sampaoli.
In some cases, it is all about only one, a coach who is 99% of his coaching team.
While in other cases, a coach without his right hand drops to 50-70% of his quality, like Rijkaard.
An interesting thing is that an assistant coach sometimes isn't good enough to be a head coach (maybe he lacks in some other parts, like a man management, motivation, maybe he doesn't have enpough of charisma to be a head coach and to be followed by his players etc, but he is a Goat in tactical knowledge and ideas).
So, when you guys are talking about Barca and Sampaoli, I hope that he would come with an assistant coach with whom he won titles in the last years.
On one hand, it is possible that Sampaoli is 99% of his coaching team.
While also, it may be that an assistant is 30-50% of his success, like in lots of other cases.