وَالْإِيرَادُ الْمَذْكُورُ أَيْ إِيرَادُ الْمَعْنَى الْوَاحِدِ بِطُرُقٍ مُخْتَلِفَةٍ فِي الْوُضُوحِ لَا يَتَأَتَّى بِالْوَضْعِيَّةِ
Presenting the same meaning through several ways differing in clarity is not achieved simply through conventional assignment.
The argument returns to bayān's definition. If several words have each been assigned the same meaning, on what basis should one assignment itself count as clearer than another? The question concerns the conventional relation as such, not delivery, memory, or literary elegance.
The claim is carefully restricted: it addresses variation as a feature of the bare conventional indication. Later discussion considers whether some hearers may nevertheless recognize certain familiar words more quickly in practice.