Not every plural is a case of taghlib. If all members belong to the same category and the ordinary plural names them, no special predominance need be inferred. Taghlib emerges when the same formulation encompasses distinct genders, names or perspectives by privileging one form.
The plural al-tullab on its own does not prove a particular act of taghlib without context. By contrast, al-abawan embraces father and mother under a dual based on the word ab, “father.”
The critical question is not simply whether the form is plural or dual, but whether two distinct terms or perspectives are being represented by one.