According to Ornstein we won't buy any new players after Laca, unless more players leave. As Wenger stated in June that we will sign 2-3 players at maximum, it is realistic.
Current squad:
GKs: Cech - Szczesny -
Ospina - Martinez
RB/RWB's: Bellerin - Oxlade - Maitland-Niles -
Debuchy - Jenkinson LB/LWB's: Kolasinac - Monreal - Gibbs
CB's: Koscielny - Mustafi - Holding - Mertesacker - Gabriel - Chambers
CM's: Xhaka - Ramsey - Wilshere - Cazorla - Coquelin - ElNeny
(R/L)AM's: Alexis - Özil - Perez - Walcott - Iwobi -
Campbell - Jeff
ST's: Lacazette - Giroud - Welbeck
I'm assumung that there will be minimal changes, so I'll just leave out players who could leave and have no impact on new signings:
One of Szczesny and Ospina (hopefully the later) - Debuchy - Jenkinson - Campbell
Cech
Holding - Mustafi- Koscielny
Bellerin - Xhaka - Ramsey - Kolasinac
Özil - Alexis
Lacazette
Backups in order:
GK: Szczesny - Martinez
CB: Mertesacker - Chambers - Monreal - Gabriel
LWB: Monreal - Gibbs
RWB: Oxlade - Maitland-Niles
CM: Cazorla - Wilshere (both never fit) - Coquelin - ElNeny - Oxlade - Maitland-Niles
AM: Perez - Iwobi - Welbeck - Oxlade - Walcott - Jeff
ST: Giroud - Perez - Welbeck - Walcott
I would trust this squad to achieve something with a better manager and with fit Cazorla and Wilshere. Assuming that Cazorla and Wilshere are staying fit would be dumb, or we return to Coq/Neny, so a CM is much needed.
Another annoying point: we have plenty of CB's, but most of them are mediocre, only Koscielny is very good. Holding and Chambers' lack of experience, Mustafi's overconfident passing, Gabriels rashness, Mertesackers and Nachos non existent pace makes all of them not the greatest starting option. Replacing two of them with another world class CB would be great, but the good thing about 3-4-3 is, that it helps our not so great CM and CB options to not be exposed that often.
Keeping Perez and playing him is essential in case we won't buy a new attacking midfielder. We need a good backup technician, in case Özil or Alexis can't play. Iwobi isn't ready yet.
How would you feel with the current squad, if we are done with transfers these windows after Laca?