You are right to worry about Tottenham big squad even though new signings like Mohammed Kudus and Morgan Gibbs-White (if that deal happens) are exciting and show team wants to win. With Maddison and Son and Kulusevski and Manor Solomon already there adding more attackers makes team very crowded. It is almost certain Tottenham will sell some players as teams can not have too many expensive players in same spots especially with money rules and keeping everyone happy and playing.
It's a norms for a team that qualifies for major European tournaments to strengthen their squad or do you expect them to go into the Champions league looking weak as they were last season? No, asides that, Tottenham had a bad performance in the previous Premier league season so for such not to reoccur they've signed a coach they feel would help them improve and are giving him Premier League proven players to finish in a better position and attract more good players next season. Tottenham is not a team that performs very well in the Champions League so I'm not expecting much from them in that tournament but the current signings would improve their Premier league performance.