Good analysis.Overall: In terms of talent we are as good as anyone in the world. That said there is still room for improvement. Let's review.
Fullbacks: Trent Alexander Arnold and Robertson both provided double digit assists in the attack and were reliable in the back half. As good a starting pair of fullbacks in the entire world. We will be losing Moreno and Clyne. But backups can be had cheaply or we can even promote from within, Hoever being an extremely bright prospect.
Centerbacks: Virgil Van Dijk is the undisputed best defender in the entire premier league and won Player of the Year. Gomez, Matip, and Lovren are the deputies. In terms of talent the deputies are sufficient, in terms of health they have all been quite injury prone at times. Of these three I'd most like to ship off Lovren and acquire a healthy CB who has the potential to develop into a starter long term.
Goal: Alisson won the Golden Glove in his debut season and has instilled an absolute confidence in his defenders. No improvements needed here. We will probably sell Mignolet and look at a new backup keeper. We recently signed Jakub Ojrzynski but at the tender age of 16 he is likely at least 3 years away from even seeing time as a backup.
Forwards: Mane and Salah shared the golden boot with 22 goals apiece. Simply brilliant on the wing. Firmino plays the central position beautifully, scoring goals and setting up his teammates. One of the most formidable front 3's in the entire world. But we seriously lack depth. If Any of those 3 go down we are in serious trouble. Investing in a rotation quality striker/winger would be a smart decision. If we can afford to rest Firmino, Salah or Mane at times, that would be a good thing,
Central Midfield: Henderson, Fabinho, Keita, Gini, Milner. Fabinho has settled in nicely, justifing our excitement with his early signing this year. Keita has yet to fully show his powers but hopefully will provide that creative spark we have been seeking. Milner is getting long in the tooth but provides energy and experience. Hendereson and Gini are solid box to box players. We might need to add one creative option/midfield maestro type to add an extra element of creativity and control against bus parking teams.
Attacking Midfield: Lallana, Shaqiri, Chamberlain. A bit of an underwhelming group. Chamberlain missed the whole season due to his massive injury and there's no telling if he can ever make a full recovery. Shaqiri has shown impact at times but then gone quiet for long stretches. Lallana has had a forgettable season and we will probably move on from him. Attacking mid is the area that could use the most improvement. A true, creative #10 is still a need after the Fekir deal fell through and we lost Coutinho to Barcelona. Dybala would be the dream signing, but other very good options are out there. Unfortunately their price tags will be quite high in today's market but hopefully the transfer team can pluck another gem.
Overall transfers: We have struck gold in back, to back, to back seasons. First Mane, then Salah, then VVD, then Alisson and Fabinho. The transfer team is simply on a roll. If we can add 2 more starter quality players this upcoming season, there is no doubt in my mind Liverpool should be 'favorites' to win the league. If we simply add 2 rotation quality players who will contribute in 20-30 games per season, that would still boost our chances to compete with City immensely.
The past three summers we've signed players who can start a match against any side in Europe, and released/sold/loaned those at the bottom of the squad in terms of quality.
This has improved the best 11, and has created an interchangeable squad of about 14 or 15 similar level outfield players from whom an 11 can be picked without the level of the side dropping too much.
What we now need is more of the same, one final summer of it in fact, signing 3 or 4 players in order to expand that 14 or 15 to 17 to 18, topped up with a couple of outfield squad players who would be used enough to justify having them here, but maybe not regularly.
For me it's about replacing Clyne, Sturridge, Moreno, Lallana, with younger, fitter, better alternatives, with the likes of Shaqiri, Lovren and Origi filling out the squad if not upgraded themselves.
There is little point having 25% or more of your squad as rarely used or emergency only players.
They don't justify their wages, the better players get overused, and anything more than 2 or 3 injuries in that better group of players seriously affects your CL and PL chances as well as the cup competitions.