I've been on the other side. My company was only promoting from within, and honestly it wasn't working. The engineering department was filled with people with I

I've been on the other side. My company was only promoting from within, and honestly it wasn't working. The engineering department was filled with people with IC only contributions, and no one knew how to manage or could mentor others. They knew it wasn't really working, but didn't know what to do/change. At some point they hired someone external, and damn, he was amazing and could mentor the other managers. Sadly, he left quickly.