As I have found in all my projects... when they bring in new American and western leadership, without a full immersion in their DNA....the new team members may cognitively recognize the company culture-- but frankly defer to their own past ways.
For the auto industry if former Ford, Mazda, Toyota, GM or other brands.... in most cases I see them fall back on the former company norms and practices....and not really embracing the new Culture unless strong mentoring takes place....
This goes the same for other business sectors. I see a few exceptions
BTW in Korea, all the major Chaebol have deep immersion into the respective corporate culture. These "boot camps", most lasting for 4-6 weeks, cover all aspects of the firm's operation.
In addition to classroom learning, they embed the new employee in actual day to day operations. For example, this may include a week on the line in manufacturing, or on the floor in their retail operations, and time in a service center. I even know a Korean food brand that requires it's new executives to work in their restaurants alongside a chef in food prep for a week.
All said, hires regardless of rank and title are most often given a brief orientation then expected to jump into their new job. This is a reality.
My recommendation as they are the face of the company the team also gets structured ongoing coaching and mentoring that shares the company's Culture and DNA.
This needs to be a priority... as it's easy to push off with urgent business matters taking precedence--the Urgent overtaking the Important, the later contributing to long-term success, missions, and goals.
Here as always....