Chelsea main hunt is De Ligt, but the agreement between the two parties is very complicated so far, especially since Bayern Munich has interfered in this transfer because Bayern Munich offer is bigger than Chelsea offer. Perhaps from this Chelsea turned their attention to Kalidou Koulibaly who seems to be the most appropriate solution for their defense next season. I think Tuchel besides getting Kalidou Koulibaly he will also monitor the developments that happen to De ligt. he really wants to get De ligt.
If both of them are still being targeted by Chelsea at this time, then it is better for Tuchel to try to get one of them because they can both be placed into Chelsea's defense next season. But I would prefer that Tuchel could compete with Bayern Munich in terms of his bid for De ligt, although other options like Kalidou Koulibaly aren't bad for Chelsea either.
That's my opinion and what do you think?