What you can do is add another goal threat to the right to replace Bale. I would surprised if Gil scores more than 3 goals in the league this season. He might set up a few however. There is clearly an over reliance on Kane and Son (and I don't trust Kane to put in 100% anymore). We seem very reliant on counter-attacking still and that is where Son shines, without him I can see us being put under siege without much of a threat going the other way against better teams.
As you said, we need a bigger goal spread too, if you remove Kane's and Son's goals from last season then Ndombele with 3 goals was the best one that is still left in the team. Moura/Bergwijn/Alli/Gil/Lo Celso need to get up to 3-5 goals each but I can't see that happening magically.
Lucas scored 10 league goals in 2018-19. Dele is well capable of getting that too - he got 8 in 25 games the season before last even though he wasn’t playing well. If we can get 15-20 out of those two (instead of the 3 they got last year) that would fix the problem. It’s optimistic but not ridiculous to hope for