Jorginho can raise the floor conceptually AND we can look worse without Partey. And I think that's doubly true because we haven't yet figure how to accommodate the difference between him and Partey.
Yes, we've had some better performances with him in the team but I'd think we'd all agree they weren't comparable to to how we were performing prior to Everton with Partey in the side. So that fluency is not there yet.
Then when you swap out Ode and slot in Vieira, your midfield is even less cohesive because he's also not been in the first XI much.
Longer term, a reserve midfield like the one we put out against Lisbon should be able to win but the fluency isn't there yet and I'd attribute that to the fact Arteta hasn't figured out how to efficiently rotate.