Exactly my point in the original post. There is a lot of dead weight in the squad, which is 30 players large, not just a match day squad of 18 who are selected.
To be a top team, you don't just need a great starting XI, you need a great bench and then you need good depth outside of the match-day squad to cover for injuries / multiple competitions / Xmas schedule / international weeks etc. Logic dictates that you work on replacing the players that MOST need replacing throughout the squad and the starting lineup, rather than one of the better players in the starting lineup just because he can be upgraded (for a large fee).
Managing a roster is surely a very challenging role which requires multi-year planning and structure.
@Zatara the reality is that selling 9 players in your 30 man squad mean that you need to replace them with 9 players ... sure some of them can come from the youth team, but that just perpetuates the problem of filling half the squad with players who simply are not going to challenge for a starting lineup position in a team that wants to become a challenger to the EPL Top 4.