Compound jinās has two analytically distinct layers: (1) resemblance in sound and (2) divergence in lexical segmentation. Repeating a single word lacks the second layer. Likewise, simply rhyming two different phrases is not enough to meet the definition.
“Dhā hibah” means “possessing a gift,” whereas “dhāhibah” means “departing.” The first is a short expression consisting of separate units; the second is a single derived word. The rhetorical figure depends on this difference.
That also distinguishes compound jinās from mumāthil, in which the two matching expressions are single words of the same broad grammatical type.