It has nothing to do with weak or strong for me. It's just business. We get so conditioned by the numbers being meaningless that we forget that someone is actually in charge of the numbers. If they can save 10/15 million on every player they try and sign over a five year period that's a huge amount.
Also it's not really a threat from Villa's POV. It's a conversation that two executives would have. From Villa's POV in planning for next season you will have asked City if they're buying Luiz back. That would, I imagine, be City's "in" to discuss how they could get a Grealish discount.
Again this is sort of moot as it's not happening, but it's just more interesting for me in terms of understanding the way we operate our player trading department.