Khan's pay isn't public but is thought to be in a band between 6 million and 8 million Swiss francs ($6 million to $8 million). In an era of belt-tightening, Julius Baer can ill-afford to pony up that much (for comparison, Collardi earned 6.5 million francs in his last full year as CEO of Julius Baer).

Collardi's pay was opposed by nearly two-thirds of Julius Baer shareholders six years ago in a non-binding vote – a first for Switzerland. Since then, Julius Baer has been at pains to be more deferential to shareholders. Collardi then had to leave millions on the table the year he left for Pictet, as finews.com reported.

For his part, Khan has expressed little inclination privately to leave Credit Suisse, where he is the natural heir to CEO Tidjane Thiam's throne. Like CEO Sergio Ermotti at UBS, Thiam has failed to give his top management talents any hints on their career trajectory, even as Credit Suisse plans for what's next following a three-year restructuring.

Delicate Succession Dance

The French-Ivorian CEO is wary but respectful of the 43-year-old Khan (Thiam was guest of honor at a recent unit event spearheaded by the private banker). In turn, the ambitious Khan feels the moment is nearing that Credit Suisse needs to reveal what the bank has in mind for him, a person close to him says.

In short, Lacher must navigate the delicacies of his former shop, Credit Suisse, for Julius Baer's succession planning. He also needs to chaperone the «pure play» wealth manager into a more digital era, all while facing headwinds besides the money laundering scandal and scouring: evaporating margins, negative interest rates, a glut of regulation, and geopolitical uncertainties hitting client sentiment.

Lacher won't be the figurehead of this era; instead, he needs to find the CEO who will take on the job. Unlike in more kind environments, Lacher has one shot to get succession right – anything else would represent a failure to his tenure.