The phrase “al-taʿbīr ʿan al-maqṣūd” concerns successfully putting the intended meaning into words. Attractive language that fails to communicate the actual point does not demonstrate this faculty.
Suppose someone asks what distinguishes a particular book. Lengthy but irrelevant praise may sound polished while leaving the central question unanswered.
Fasāḥat al-mutakallim includes the ability to form linguistically sound, clear utterances for the intended content. Balāghah will introduce a further requirement: that the chosen expression suit the audience and circumstances.