I agree with you, right now I don't see another player like Martinez, Inter knows very well that if they let Martinez go it will be a hard blow, I would take care of him and give him a good contract that guarantees me the whole league and at least another league more, I'm talking about at least 2 more years with Inter, and if he arrives on loan or whatever Lukaku will be the ideal partner for him, I wouldn't be angry at all if Inter agrees like that, for me it will be a very good team hard that if he knows very well what he will look for, however if this eventual team emerges, it is obvious that they will be in the UCL, then he would think at that time of hiring more forwards.
Darwin Nunez is a worthy replacement for Sadio Mane who has made an outstanding contribution to Liverpool.
Jota and Diaz are increasingly compact with Jurgen Klopp's strategy so that next season Liverpool are very ready to compete again to win several leagues.
One more player's position that must be prepared by Jurgen Klopp is the midfielder. Currently Liverpool midfield is occupied by Thiago and Henderson. The age of the captain has begun to be old, the targeted player is to cover the post left by Hendo.
Honestly I would bet on Diaz, I know that Slah is a fundamental piece in the team, but a good team has to have a good midfield, for now they are not so bad, I think that if I were the coach I would leave only Luis Hernandez as forward, and I would build a more solid team from the midfield, well I am one of those who think that if you dominate the midfield, you have total control of the game.