When Weil, Gotshal & Manges announced plans to wind down last week, the collapse of the 95-year-old law firm stunned the legal industry. Weil had roughly 1,200 lawyers, more than $2 billion in annual revenue, and a roster of major corporate clients. Yet the departure of a handful of powerful partners helped set off an exodus that threatened the entire institution.

At Weil, one of those performers was Michael Aiello, the firm’s highest-paid partner and a leading dealmaker who reportedly earned more than $20 million annually. Aiello oversaw a corporate practice of more than 600 people and maintained a close relationship with longtime leader Barry Wolf. When he left for rival Cravath in September, taking five partners with him, the departures helped unleash a broader wave of defections.

Weil’s predicament illustrates the vulnerability of businesses built around individuals whose commercial value gives them extraordinary leverage. Star performers attract clients, generate revenue, and recruit other talented people. But when those relationships and capabilities remain concentrated in a few hands, the company becomes increasingly exposed if they leave.

The same risk can exist at investment banks, where a rainmaker controls relationships with major clients; at consulting firms, where senior partners bring in much of the business; and at technology companies, where a founder or influential executive becomes synonymous with the organization’s success. Even within smaller divisions and functions, teams can become overly dependent on a single high performer whose departure leaves a gap in expertise, relationships, or leadership that others aren’t prepared to fill.

For leaders at every level, the challenge is capturing the benefits of exceptional talent while ensuring their teams and businesses can withstand losing it. That means expanding client relationships across teams, building a deeper bench of people who can generate business, and distributing knowledge and decision-making authority. Succession planning must account for the departure of influential revenue generators as well as the person at the top.

For ambitious professionals, the episode raises a related question. How much of your career’s value depends on the continued success of your employer or the support of one influential leader?
The lesson is to build two kinds of career capital simultaneously. One is the value you create within your organization. The other is the value you can carry elsewhere.

That means cultivating relationships beyond a single influential sponsor, developing expertise recognized outside your company, and understanding how the business generates revenue and makes decisions.