Doesn't mean he won't either.
I'll agree that their team was worse than ours, but then our team has 7 starters that either weren't used by the previous manager, or are brand new signings. Many of which were slaughtered as being "cheap options"
In place of Arteta, let's use Klopp. He joined the dippers in 2015, and won nothing until 2019 against us. 4 years to win a trophy, 5 years to win a title.
Klopp had vastly more top league experience that both AP and Lego, and it still took him 4 seasons to get the balance right.
The core point has already been raised on here. It takes time to build to a team that can challenge for the title, regardless of your experience, unless you have the wealth of a nation backing you.