- The Wilsons are angry at the Smiths for the way they parked their car.
- The Wilsons haven't hated this Smiths this much since they moved.
- The South hasn't hated the North this much since they lost the Civil War.
- The red team likes the blue team because they feed their pets.
- The red team likes the blue team because they found out the blue team gives to their charity.
In the first sentence, it's clear to me that "they" and "their" refer to the Smiths. Is that based on a grammar rule, or just meaning? It would be nonsensical to be mad at someone for the way you park your own car, so the meaning does give it away.
The second sentence seems less clear for some reason. Did the Smiths move or the Wilsons move?
Is the third sentence wrong usage? If you know that the South lost the Civil War, the meaning is clear. But should grammar rely on historical knowledge?
The fourth sentence seems clear. The blue team feeds the blue team's pets? Is that right?
Why does that work differently in the fifth sentence? I guess the "they found out the blue team" eliminates "they" meaning the blue team so it must mean the red team? What about "their" does it refer to the blue team's charity or the red team's charity?