Hmmm, Liverpool's attack and defense are both somewhat weak, nevertheless don't see any flaw in their squad. They have plenty of talented and experienced player in their ranks.
In defense, Kerkez, Van Dijk, Jacquet, Frimpong and Araujo are all talented. In midfield and attacking lineuup, they have player like Gravenberch, Mac Allister, Wirtz, Szoboszlai, Gakpo, Barcola, Isak and Ekitike. In the last transfer window, I could see they also spent over 260 million.
So I see no reason to add new player to the squad in winter transfer window.
Imo, Liverpool's current problem is tactical. As bonding among player grows stronger, their performance will gradually become even more powerful.
You are absolutely right. Liverpool has a decent squad, both defensively and attacking, the problem they're facing is tactical integration.
Mo Salah, Luiz Diaz, Alexander Arnold and Robertson have been the key players for Liverpool for the past 3 years, but they've all left. Now half of the squad is filled with new signings who are still trying to integrate the team, some players are still trying to establish and communicate with each other on and off the pitch. Just like you said, " As bonding grows stronger, their performance will gradually be even more powerful".