How can Srila Prabhupada be the center when “the shastra is the center for all”?

Srila Prabhupada says in his purport to Sri Caitanya-caritamrita Madhya-lila 20.352 that among the sources of knowledge of dharma given by one’s guru, other saintly persons, and shastra, “the shastra is the center for all.” Yet it is seen in many sampradayas that the acharya is still very much central to the practice and faith of the devotees. So, if the actual center is the shastra, then what does it mean to a community to keep the acharya in the center? This question is discussed and answered in this video by Krishna Kirti dasa of the ISKCON India Scholars Board.