The United States’ third-largest bank by assets has been plunged into crisis by revelations that its branch staff created as many as 2 million accounts without customers’ knowledge in order to meet internal sales targets.

John Stumpf, the bank’s chairman and chief executive, left last week in response to a public outcry and the bank put Tim Sloan, a 29-year Wells Fargo veteran and Stumpf’s heir apparent, into the CEO role.

Once viewed as an unambiguous asset, Sloan’s long tenure at the bank is now prompting questions about whether he has the necessary critical distance to overhaul an aggressive sales culture that allowed the misconduct to fester for years.

“There’s something wrong with Wells on a cultural basis and you’d think they’d need to bring in an outsider to fix it,” said Paul Miller, an analyst with FBR Capital Markets.

Wells Fargo declined comment.

The San Francisco-based bank has long had a reputation as a place where a tight-knit group of senior managers worked together to deliver industry-leading returns.

But the recent episode has made the closeness of top executives look like a handicap.

During Sloan’s first earnings call last week, Miller asked him whether the bank would bring an outsider into its executive leadership ranks.

“It’s a fair question and one we’ve been getting asked,” the new CEO replied. However, Sloan said that following recent changes, the board “is comfortable with and very supportive of the management team.”

CHANGE IS HARD

While the bank needed to make a change quickly and Sloan is a proven commodity, Columbia Business School professor William Klepper said the board should have named Sloan CEO on an interim basis so it could conduct a thorough search including outside candidates.

“It’s very difficult for anyone within that organization to make a change,” Klepper said. “The last thing they might sense is the water they’re swimming in.”

Klepper pointed to Lou Gerstner, a longtime American Express (AXP) executive who came in as Chairman and CEO of International Business Machines Corp in 1993 to lead a successful turnaround of the lumbering computer giant, as the prime example in U.S. business of the value of bringing in fresh blood.

Most major U.S. and European banks have seen shake-ups of top management and their boards of directors following the financial crisis of 2008.

Wells Fargo, which avoided the sort of crises suffered by rivals during the financial meltdown, has seen very little change at the top, and that seems set to continue.

The bank did separate the roles of chairman and chief executive following Stumpf’s departure, with Stephen Sanger, the board’s lead director, chosen as chairman.

But the bank did not announce any new faces to its board, which has some of the longest-tenured members among major U.S. banks.

BOARD VETERANS

Three of Wells Fargo’s directors have been in place since the 1990s. The trio helps put the average duration of service for a Wells Fargo director at 9.7 years, compared to 8.5 years for companies in the S&P 500 Index, according to a report by executive search firm Spencer Stuart.

There have also been questions about the wisdom of appointing Mary Mack, a former wealth management executive, to lead the retail division at the center of the scandal.

The consumer bank had previously been led by Carrie Tolstedt, a 27-year Wells Fargo veteran. She left the bank last month.

Mack joined Wells Fargo when it acquired Wachovia at the end of 2008. Wells Fargo declined to make Mack available for an interview.

“Can you just give us a sense why, because we’re looking for a culture shift or culture enhancement change in the business model and that’s a big ask, so I’m just wondering what you saw in her,” Morgan Stanley analyst Betsy Graseck asked Sloan last week on the earnings call.

Sloan responded: “I saw an executive with decades of experience in the financial services industry and decades of experience at Wachovia and Wells Fargo, who has been through a variety of challenges in her career, and who is an incredibly effective leader.”