I can say it was an amazing start for Walter Mazzarri in Napoli, After all the points they lost with Rudi Gacia, it seems Walter Mazzarri is in a better situation in Napoli because Rudi didn't have a good relationship with other players and it was a reason for Napoli to et him but with Mazzarri they don't have any of these problems.
Indeed. It is a good start done by Mazzarri, he can manage Napoli squad winning against Atalanta. Atalanta isn't a small team in Serie A, it is a quite strong team. So, winning against Atalanta proves that Mazzarri has a better capability to manage Napoli than Rudi Garcia. With this good progress, we can assume that Napoli can be competitive again, they probably target to join the race of the title. I really hope that the competition for Scudetto isn't for Inter and Juventus only, if more teams join the race will be more interesting.
Yes, it seems Mazzarri knows better how to have a good relationship with the players and understand to apply proper tactics. It is what Napoli players can't get under Rudi Garcia's management.