I mean you're wrong here (as is the PL site then). 'On 26 December 2019, Arteta took charge for the first time as an Arsenal manager for their
Premier League match against
Bournemouth which ended in a 1–1 draw, thanks to a second half equaliser from
Pierre-Emerick Aubameyang.'
We were 11th on December 25th. So, he took over when we were 11th. He was in the stand for the game before that, but he wasn't in charge/managing.
Emerys PPG for that part of the season was 1.27. (18 games). (11th)
Artetas PPG for the rest of the season was 1.65 (20 games). (6th in this period).
Arteta also won the FA Cup. So, for me, his first season was a success relative to how he picked up the team.
P.S For the person who said Arteta was in charge for over 50% of the season, yes, it was about 52%, but I imagine you thought it was like 65% and you were trying to make a point which isn't true.