It's a logical argument but it becomes subjective I suppose.
I would break it down by positions and say 2 for each position and some youthful 3rd choice fillers..
ST - Expect Solanke to stay and 1 marque signing needed.
LW - I don't rate any of our LWs. Perhaps Moore as a 3rd choice but I think we need 2.
RW - Kulusevski and Kudus. Cool, I can live with them but there are huge question marks around their fitness. I think we need to bring one in.
CAM - Maddison and Xavi. We know Xavi will miss most the season, so we should bring one in, or move Kulu there and bring in a RW.
Then you have a 2-3 youth prospects around the squad as 3rd choice for the positions. Moore, Odobert and Tel are the same position, so I'm taking Moore and binning the other 2.
Let's not be shocked to see Lankshear, Yang and possibly Odobert playing on permanent contracts for lower division clubs within 1-2 seasons.
Whatever way I look at it, I believe we need 4-5 senior players of a high level coming in as an absolute minimum for the attacking positions.
Then we need a GK, LB, CB and although we seem to be collecting them - we do actually need a good CM. Got plenty of below par CMs that will be hard to shift now so expect little movement there.