New CEOs often inherit a leadership team and hesitate to make changes, especially in a stable company. Effective leaders immediately assess if the current team is right for the future agenda. Postponing necessary personnel changes is a critical and common mistake that derails success.

In a turnaround, a leader's most critical first step is restructuring their direct reports. McLaren's CEO replaced every key leader—CFO, HR, commercial, etc.—to create a unified group that could then drive cultural change down through their own departments.

When diagnosing a failing department, stop looking for tactical issues. The problem is always the leader, full stop. A great leader can turn a mediocre team into a great one, but a mediocre leader will inevitably turn a great team mediocre. Don't waste time; solve the leadership problem first.

A CEO with good intentions can still foster a poor culture by tolerating a toxic senior leader. They keep this high-performer for their P&L impact, allowing "cancer" to spread. The CEO must remove them, even if it's painful financially in the short term.

A CEO who stays too long creates an organization optimized to respond only to them, causing other skills and response mechanisms to weaken. Leadership changes are healthy because they force a company to develop a more balanced and resilient set of capabilities, breaking the imperial CEO model.

When Home Depot's culture began to erode due to a mindset that prioritized cost over people, the board's solution wasn't a new initiative, but a leadership change. Ken Langone credits the new CEO, Frank Blake, as a "founder" for his role in restoring the company's core cultural values.

To fix a failing company's broken defaults, changes must be abrupt and aggressive. Gradual 'change management' fails because it doesn't create the necessary shock to the system or repel misaligned employees who are part of the problem.

Reflecting on his first years as CEO, Seth Bernstein's biggest regret was not installing his own trusted people into key roles faster. He advises new leaders that executing a transition requires a team fully bought into the new vision, emphasizing that proactive change is a positive force.

Radical turnarounds often fail under existing leadership not from a lack of knowledge, but because incumbents are too emotionally invested. They are wedded to the past and find it impossible to make ruthless personnel decisions, such as firing long-time colleagues they view as family.