I don't understand why they're trying to get Felix back.
Nkunku is fit now so he'll be playing in that false 9/support striker position. Cole Palmer had some really good games infield so if Pedro Neto stays fit he'll probably play more as a 10 and you've still got all of Jackson, Mudryk, Sterling, Madueke in the mix,
I get they need to get someone from Atletico to push through the Gallagher deal. Thinking about it Jose Maria Gimenez would be ideal fit for them at the back. Vastly experienced and cunning so he'd add a bit of edge to their defence.
No idea if he wants to stay there for eternity with Simeone but that sort of signing would elevate them back up the league if he was available in 40-50m bracket.