The only flow in the logic for me in the multi-founder scenario is that if the other person is non-technical, they are automatically considered sales etc... by default. So you can get anyone who is not technical and meet the model; regardless of their skills. It's harder to prove someone is not good at sales vs a technical person (more relevant in younger founders).

The only argument I can think of against what I just said is that the other person is not heads down building so they have more time to acquire those skills.