I mean, this has been done before and yes, there are numerous examples from Real Madrid.
I think City had one on Lavia and choose not to trigger it when he went to Chelsea.
I think it’s a risk free move - if the player develops enough to warrant a starting place at Liverpool, then we’ve negotiated a “fair” price which is under what Leverkusen could likely ask for.
If he doesn’t, we’ve banked a good fee.
There’s no downside to the structure of this deal at all.
Name 1 that's worked out? So far all you've done is name 1 that never materialised.