Currently they have anticipated a shortage of players. For Gabriel, who was a bit doubtful when he had to suffer an injury, now he has been fully entrusted to Nketiah and yesterday for Partey, who was injured, now Jorginho has been brought in from Chelsea to fill that position. I think now Arsenal are still very ready and Arteta is really thinking about all the possibilities that will happen and of course that is very good.
This week they have a pretty easy game against Everton and I think it will be a win for them with the current squad.
Nketiah has filled up the boots left by Jesus really well that I see Jesus not coming back into team easily. But the case of Partey is different, Arsenal success lies on a strong and energetic defensive midfield who can bully opponents well. Jorginho doesnt seem to have that ability to fill in the gap in Partey absence. Jorginho is way too slow and isnt that physical able to go on some tackles. His side ways and backward passes might slow down Arsenal counter which is their most effective pattern of play this season.
Nketiah might have filled in the boots of G. Jesus but, his not even 90% of G. Jesus just yet. The difference is still very huge between these two players. Nketiah isn't a play maker like G. Jesus, he doesn't really create any chances except to be positioned properly to take it wjen created. G. Jesus on the other hand is both play maker and goal scorer. When his pn the pitch, his sure to take 2-3 defenders to his side and create space for the attacks.
I think he would find it very easy to get his spot back once he returns from injury.
As fir Jorginho joining the Arsenal side, am still wondering what Arteta and the board saw but, perhaps Arteta have got a better way to use him.
Your summary on the distinction between Nketiah and Gabriel is true. Arsenal has reduced goal average so far since Gabriel's injury. Although, Nketiah has filled in well by being in the right positions often and the team has kept the composure, but the stiffness in the squad is glaring without a playmaker.
Arsenal's problem always starts this way. Unlike the time when Wenger was the manager; the playmakers start getting knocked by injuries and the team tries to balance by being more defensive and daring upfront. Jorginho is a playmaker too.