Prince's twin brother or someone who looks like prince either naturally or through surgery could make a likeness claim. There might be a few holes in this plan.

Sure, it's not perfect, I'm just going through a thought exercise to try and reason if the hypothetical I'm suggesting might be more fair than the current system. A lot of people say there are holes/deficiencies in the current copyright system. And a "perfect" system that everyone would be happy with is likely impossible.

Isn't that kind of how it already works? A software vendor licenses libraries bundled with their software and different people end up owning different parts of the final product?

In that case it's pretty clear who owns what due to the licensing involved.

I was more thinking of situations where a person, say, photographs a building they don't own or didn't design. They couldn't have taken that photo if no one built the building. But they alone own the copyright to the photo. Technically anyone who helped construct the building contributed to the creation of the photo, but have no right to prevent the photo from being circulated, sold, etc..

Let me be clear on saying that that's how I think it should be. I don't think we should stymie productivity for creating art/music, even when you are using other's creations as pieces of your own creation. But it gets murky like the case described in the article where Warhol created his own work depicting Goldsmith's work, and the courts ruled it wasn't a fair use.