Have you ever noticed that any general principle is useful up until some point and then it breaks? That is a beauty of life. This game requires a player. There is no way to automate it. There are no generic one-size-fits-them-all solutions. 

All decisions are subjective. Decision maker is a mandatory position. Discuss it. Argue about it. Analyze it all day long. But in the end of the day everything boils down to one person calling a shot. Results of your decisions are objective, though rarely fully predictable unless they are trivial or meaningless. 

It is scary but sets you free. Do your best to be smart and calculate things down the road, but remember that nobody knows a damn thing. And even this general rule, of course, has its exceptions 🙂 

So, the point here is that your perspective - matters.