The restructure, which aims to position strategic planning at the centre of the agency's offering, also sees the appointment of Leith London's Richard Kelly, who takes over from White as the executive planning director.
The appointments follow that of Robin Lauffer as the head of strategic and consumer insight across the Euro RSCG group.
At Leith, Kelly was the head of planning. He joined from McCann Erickson, having worked as a senior planner at TBWA\GGT Direct, after a spell at RPM3. He started in the industry in 1991 at KWS, staying for seven years while the agency merged first with FCA and then into Publicis.
Sheryl Wilkinson, also from Leith, joins as the client services director, replacing Joe Boyd, who is leaving the agency without a job to go to.
Langdon said: "I want the new Euro RSCG to place far greater emphasis on strategic planning than previous regimes. In Malcolm, Richard and Robin I have strategic planners at the forefront of our management.
"The appointment of Sheryl and Richard as as a team was quite deliberate. The fact that they have worked together before means they can hit the ground running."
The move reunites Kelly and Wilkinson with Langdon, with whom they worked at McCann.