@edvin For the SO article...Don't you want one Model object and two ViewModels, one per table?
1. Select a record in the left View and press Sync.
2. Delegate a call to the shared Model through the left ViewModel (could be async)
3. The Model fires an event
4. The left ViewModel receives the event, but ignores it since the data hasn't changed
5. The right ViewModel receives the event and updates its property
5. The right View is updated though binding to the right ViewModel
This way you don't need multiple Person models