Maddison had 19 goal contributions (with a team that got relegated) in 30 matches last season. KDB had 24 in 32 matches with the title winning team.
I think you can't bring up KDB without also saying how much Maddison returning is going to elevate Spurs.
In theory, Spurs 18 could be: Vicario, Udogie, VDV, Romero, Porro, Bentancur, Sarr, Maddison, Werner, Son, Kulusevski with a bench of Richarlison, Johnson, Bissouma, Dragusin, Royal, PEH, Lo Celso. That's more than competent enough to keep pace with the big boys, especially without the need to roate squad among too many cup competitions. Also worth mentioning that Spurs still have to host Arsenal and City, and those games tend to go Spurs' way. Even four points from those fixtures likely plops Spurs up into top 3.