> What exactly should the author have done differently?

Work with the other engineering manager.

This person was angry about the team's appearance, but the other engineering manager who assembled the team is barely a side note in the document.

The way you deal with these situations is by working with the other managers involved and propose better solutions.

This is a weird blog post because it's supposedly from someone in a high up engineering manager position, but it's written with a political awareness that I'd expect from someone who had never managed before or who was a first-time manager without good mentorship.