Szczesny/Ospina
Bellerin (CWBs) Mertesacker(CDx) Koscielny(CDc) Monreal (FBs or a)
Cazorla (RPM) Coquelin (BWMd)
Ramsey (I would put him as Shadow striker in right AMC spot) Ozil(Treq mb) Alexis (IFa)
Theo (AF or CFa I suppose)
As you see roles are very attacking so system must be fluid to make...