Code reviews/design critiques are extremely valuable even if you only have two developers, and they're both great at their jobs. It's not about not trusting the other members of your team, it's about learning from each others' experiences and creating a better product together.
But I agree that the level of ceremony surrounding the process will vary a lot based on the size of your organization.
But I agree that the level of ceremony surrounding the process will vary a lot based on the size of your organization.