ولا معدود أي ذي عدد وكثرة
Nor is He a numbered being comprising multiplicity.
One and countable do not have identical meanings. When a book is called one, it is one among potentially several books of the same kind. Counting two or three such objects is intelligible.
Divine unity means that no second necessary being or divine partner exists; it is not the claim that God is the first numerical member of a class of comparable divine individuals.
Fallacy: Inferring that God must be one part of a numerical collection merely because God is called one transfers an ordinary counting sense to a claim about necessary uniqueness.