Lol Harry Kane wouldn't get onto Chelsea's bench and majority of Kanes goals have come from the europa league this season. We're acting like Drogba and Remy wouldn't score goals for fun against partizan.
The problem is Modric and Bale being irreplaceable. Note that you sell a key player the past 2/3 seasons and you have thus dropped one position each season. It's no coincidence. If you had bought a top striker in the Bale Modric days and a bit of cover (e.g. a Chadli/Lamela and with a guy like Dembele/Paulinho as backup) you would be challenging for the title, not being lucky to break into the top 5. Levy just saw the cash and thought may as well.
But your problems aren't easily fixable, you just have to hope the team gel and the manager finds a system that works for all the players, you don't have the money to spend your way out and it's hard to determine deadwood when a lot of the problems is hierarchy related as well as player related.