It is definitely important to understand the culture and traditions of the country or countries your company is going to be operating in. It is also important to respect those practices. I suggest giving your managers a crash-course in local customs, especially taboos and things to avoid. For example, in some countries a bribe is polite, in some it’s offensive, and in some it’s expected. If possible, your managers should have a mentor who is native to the area that can guide them when they first begin operating in the region.
Multi-national corporations can best prepare their managers to work overseas through education. Of course, these managers must be well grounded in the basics of management that are common to all companies. However, they must also be educated in the particular issues that go along with being an expatriate. They must be educated about the particular pressures that their fellow expatriate employees will face. This knowledge will help them be more understanding and help them get the most out of those employees. Education about the local culture and ways of doing business will help the managers be better at dealing with local workers and business partners.