Effective international managers were said to be those who were adaptable

Effective international managers were said to be those who were adaptable, flexible, open-minded, speaking in foreign languages, and making friends with those of many nationalities. (Smith, 1992:46)
Critically discuss the validity of this statement and the extent to which being adaptable, flexible, open-minded, speaking in foreign languages, and making friends with those of many nationalities are relevant and sufficient qualities, capabilities and conditions for international managers being effective in the context of managing culturally diverse project teams. Draw on specific illustrative examples from case studies and/or organisations with which you are familiar.