For any product the most important quality that the team needs to have is the ability to make the right judgments There are several decisions that stare down and your ability to make the right judgments dictate the success of the product.
To make the right judgement you need data and the skill to understand the data and come up with the best solution that solves that particular problem. Any successful product has two important facets. It should be the right product at the right time – meaning the problem the product solves should be real & important and the technology should have evolved to a stage where this can be solved technically.
The onus on the PO is understand the customer and serve as his proxy when it comes to defining the road map of the product and vision. He/she will have to be the ultimate voice for the customer or the end user. The PM should understand the customer enough to know which battles are minor and which will be decisive.
On the other hand the role of the Architect who is the second person in the model, will be to understand from the product owner the needs of the customer and have a dialog on how best to solve this problem. This person is not looking for requirements to be handed down like in a waterfall model but is actively participating in the decision making process and is helping the PO modify his requirements to solve the problem for the end user in the quickest and the most efficient way that is technically possible.
Often times when we have a big product this model can be extended to be 3 in a box model where the UX person is the third person in the triumvirate He is responsible for taking the product requirements and will come up with the best experience possible for the end user who is intended to use this product.