Analyze the contrasting dynamics that Sara navigates in her interactions with Dr$.$ Acharya and Paula. Drawing on the situational leadership approach and path$-$goal theory, dissect the variations in Sara's leadership tactics and behaviors in each scenario. Illuminate the theoretical underpinnings that justify the differentiated approach Sara employs with Paula as opposed to Dr$.$ Acharya, integrating the complexities of leader$-$member exchange theory and the relevance of individual motivational factors within the team. In your critique, consider the impact of Sara's leadership adaptations on departmental efficacy, personnel development, and strategic goal attainment. Furthermore, reflect on how these interactions showcase the interplay between leadership styles and organizational culture in healthcare settings. Provide a substantiated rationale for the importance of context$-$specific leadership strategies and suggest potential implications for practice within your own professional sphere.