Don’t know exactly what BVB promises from it? In order to become the next Bellingham, it is too old for 2-3 years. Do you find gray midfield well in Dortmund?
Stuttgart must remove something baking smaller rolls than BVB. And has to rely on younger players who are not considered a mega talent but can still make the jump, Banzuzi fits the profile quite well, but should the claims actually be different for BVB?
Sorry but if you are only looking for players who can become the “next Bellingham”, then you can forget almost 99% of all players.
Bellongham is an absolute external acceptance talent. As the name suggests, there are such talents only in exceptional cases. It is difficult to find this alone, but even if you have found it, you first have to want to go to BVB. It is not as if only BVB wants to have such players.
If a Dutch U21 international who still has a lot of potential upwards should not meet the requirements, then you should be rethinking the claims.
Have a look at Frankfurt. Did they get the next Bellingham with Larsson or with Marmoush the next Haaland? No. Did both players develop so that they also had a good look at BVB? Definitely yes.