To everyone saying we shouldn't go for 5 or 6 young players, but rather sign 2 or 3 ready made, world class players: Have you seen us play this year? Do you really think a few twinks are going to get us back at the top? Our squad is not only lacking in quality, but it's also awfully unbalanced.
If you compare us to Liverpool, and say "they only needed to sign a quality CB, and they are suddenly challeging." 1. Their first team were already very good, and more than that, their players were suited to the way Klopp wanted them to play. 2. Allison, VVD, Robertson, Wijnaldum, Mane, Salah and Firmino has been involved in almost every match this season, and without such luck with injuries theit squad would be far from good enough to challenge for anything.
Another point against us going for just a few world class players is that this tactic hasn't worked for us earlier. If we buy more and younger, we can spread the risk of a flop over multiple players, and we can form the players over time.
In conclusion, everyone should realise that our squad isn't good enough to challenge next season, and probably not the one after that. But if we're patient, and build a squad with players that suit a certain style of play and who suit each others qualities, then we can start challeging in two-three years time, just as Rashford, Martial, Shaw, Lindelöf etc. hits their prime.