Relaxed about how he's going so far.
This is worth a re-read:
https://www.cannonstats.com/p/kai-havertz-the-debrief
Havertz' latest stats are all over the place because he's being rated against attacking mids after a season of weirdness at Chelsea. However, this analysis cautiously interprets him as a "normal" finisher coming off a bad spell, not a player such as Jesus with semi-permanent wobbles.
Havertz has a very distinct persona from our other options where he plays. He is a 90 minute athlete with craft off the ball. He's imperfect defensively, but aggressive, physical and durable. He's strong in the air and becomes our only properly tall player ahead of the defence. He's thought of as coachable, has a reputation for stepping up in big matches, and very likely has upside on recent form.
We have a number of possibilities at 8 on the left including Rice, Smith Rowe and Trossard depending, so it's good Havertz is dissimilar to all of them.
After the shambles at the business end of last season, it makes sense we'd want an extra tough nut who can run hard, and his attributes should make us less predictable too.
At £65m, people understandably want Havertz to have an obvious best position and "weapons", but it'd be absurd to give up on him after three solid run-outs. He'll need to find form, create and score as time passes. Arteta has a few related problems to solve, from whether Partey and Rice both play, to the left fullback position, to how the brilliant Trossard gets minutes.
Side note, but Martinelli had a big dip in output when Jesus didn't play last season, and Jesus isn't in the side now either, so I wouldn't be quick to blame any Gabi disconnect on Kai.