Even nowadays, in the dawn of the 20s, I often encounter believes that managing a team means leading them both in people and technical ways. A proper manager should be a perfect people person, with strong technical skills, sometimes a scrum master or project manager as well. And let's say he'll be driving two projects in three different locations.
Passionate engineers spend a significant amount of time learning new technologies, trying some new approaches and coding stuff for themselves. They are usually in love with interesting solutions, sometimes this can even distract the business goals of your company as the biggest enemy of good enough is perfect.
But what if the manager trying to guide the team also in a technical way will make a dumb decision - do you believe the team will stand up and ask for re-evaluation? This requires quite a high level of courage and seniority.
I believe the manager should focus on people management and business, set and discuss career paths, help with feedback sharing, make sure cooperation goes well and help two colleagues, who hate each other for ages, to bury the hatchet and cooperate. Identify strong skills and setbacks of the engineers, help them maximize the benefits of their masteries and reduce the harm of their weaknesses.
Understand what are the blockers for engineers to work really effectively and assist with their removal (obstacles, not engineers :) ). Drive the changes of environment, less the processes and just don't replace the work of architects and senior engineers.
Actually, this works both ways - if you want to annoy and demotivate your senior engineers, promote them to managers just because they are the most experienced engineers. Let them suffer the work they don't like and fill their calendars with meetings, so they can't code. And finally, let them know how surprised you are that they are not able to fulfill even the basics of management.
This doesn't mean the manager shall not participate in technical meetings - the go&see principle is still extremely important. But use your soft skills to moderate and unblock discussions whenever the team gets stuck. Make sure business needs are kept on mind. Help the team to break huge tasks into actionable pieces and ensure all stakeholders are contacted. And let the engineers and architects do the work they understand, want, and love.