Nach einer Studie von Dave Ulrich gibt es sechs verschiedene Kompetenzen, die HR-Manager auszeichnen. Eine davon ist der "Culture and Change Steward", eine andere der ebenfalls von Dir genannte "Credible Activist"

The 2008 awards are based in part on the HR Competency Study completed by Dave Ulrich in partnership with the Society for Human Resource Management. This study determined a model of six competencies that distinguish HR professionals and are necessary for HR professionals and their departments to help build the business. The six competencies are: Credible Activist, Operational Executor, Business Ally, Talent Manager/Organization Designer, Culture and Change Steward, and Strategy Architect.

http://www.shrmnm.org/default.asp?PageID=10008273

Examples of culture and change steward activities: aligns individual behavior and organizational goals, identifies and engages people who make change happen, sustains change through HR practices, designs and delivers HR practices that create and maintain the desired culture, shares knowledge across organizational boundaries, makes culture management a business priority, frames culture that engages employees, translates culture into management practices, makes the whole organization more than the sum of its parts, helps employees find purpose and meaning in work, manages work/life balance within the organization, ensures that the culture of the organization is recognized in the mind of the external stakeholders.

Aus dem Zusammenhang gerissen macht eine knappe Übersetzung meiner Meinung nach wenig Sinn. Man müsste vielleicht etwas umschreiben, z. B. "ein HR-Manager, der die Unternehmenskultur ins Zentrum seines Handels stellt und die Einführung von Änderungen erleichtert". Zugegeben, etwas lang.