My general $0.02..... We are setting ourselves up to run a 4-3-3 and 4-2-3-1 situationally. That give us 4 different MF roles..... DM, CM, AM & SS.
DM - this is an "Arteta 6" which is more of a 6/8 hydrid. Plays the 6 in the 4-3-3 or 2 man base in the 4-2-3-1. The depth here likely looks like Zubi, Rice, MLS for the 4-3-3 and Rice, Bruno, Zubi, & MLS in the 4-2-3-1.
CM - a legit 8 in the 4-3-3 (play with 2) or the "AM" in the 4-2-3-1 if we need/want the double pivot with a defensive edge. Depth here is Rice, MO, Bruno & MLS
AM - more of a traditional 10 for a 4-2-3-1. depth is MO, Eze, Merino & Nwaneri
SS - more of an attacking/roaming AM for the 4-2-3-1. depth is Eze, Merino & Nwaneri
Personally think we start seeing more and more 4-2-3-1 this season. I think we see Rice, Bruno & Zubi as the primary 2 man base with approx 3000-3500 min per player (rather than the 5000+ Rice & Zubi got last season). Think MLS gets his minutes in MF. I'm thinking he ends up 1500-2000 across all comps with most of his starts coming in domestic cups but with a few odd starts across the EPL and CL group stages.
Outside of an unexpected exit, I agree that Nwaneri is the likely odd man out. I think/hope that we send him on loan or sell with a reasonable buyback because I think his near future may be in an AM/SS/F9 type role (effectively replacing Merino) and all of our other AM/SS depth is 27yo+. Depending on other exits, think there is a chance we keep him around and get him minutes across AM/SS, RW & F9.