You would struggle to establish that "A's stabbing of B causally led to B's descendants being poor". It's not enough to argue that A stabbed B and B is now poor therefore A caused B's poverty, which would be a post hoc fallacy.
I'm pretty sure you posted this after my edit, but in case you didn't, please read that. I'm not the one that came up with this contrived "A stabs B" example, and I never claimed that "for any A that stabs B, then B is causally at a financial disadvantage in the future" (though I would claim this effect in the real world, on average, but that's off topic).