Ozil and Laca are the key issues. Pepe disappears in second halfs but he usually starts brightly, hopefully getting his fitness sorted will see him right. I'd even stick with a rotation of the kids on the other wing for another season, Nelson, Saka and Martinelli are all talented players who deserve game time. If we didn't have so many other holes in the squad I'd maybe sign a winger but for now I'd let them develop and see if we can sort out that position internally.
Ozil and Laca as our 9 and 10 though are just way below what we need. Laca is our main striker now and has 5 goals all season, thats awful. Ozil as our number 10, with plenty of game time this season, has 2 assists (I think one was a corner and the other wasn't even a real assists, a cross that was handled for a pen) and 0 goals.
If thats the return you're getting from your 2 central forwards of course you will struggle to kill games off. You'd have to wonder if Willock and Nketiah could do any worse.