Claudius Been looking at this, and I reckon you're not far off what we could do.
I'd look at releasing Martinelli this summer to bring in that upgraded winger.
I'd prefer Yıldız to Barcola at this time, but from what I gather, Yıldız is not going to move.
We need at least one more "clever" forward who can create chances and link play. That's been the leading criticism of what Martinelli brings, and it's a criticism Madueke hasn't fixed despite being more than capable beating his man. So left wing is where it's at.
Yıldız could be that "more mobile Trossard" we've been speculating on, as he can drift central or play as a second striker as well as beating his man and having good running power. So it's a shame he is unavailable.
Ben White will stay at Arsenal unless there's a Biblical miracle. White would not currently pass a medical as he's been in rehab for that MCL injury against the Hammers. If White somehow gets fit and stays that way we could look to flip him in winter or next summer. £20m is not going to happen.
This means we'll be heading into next season with two at least semi-crocked right backs plus Mosquera unless we sign a player. Palestra sounds alright but I'm guesing the position will still be troubled by risks and contingencies.
I'd consider shipping one of Maduke and Eze out. Both are very good players with upside we've yet to see. However, Eze's a luxury player and Madueke's an inconsistent player. Both are going to be "finisher-zoned" among Arteta's romantic interests to a great extent.