أَنْعَمَ اللَّهُ عَلَيْهِمْ. رَزَقَهُمْ عِلْمًا نَافِعًا.
Allah bestowed favor on them. He granted them beneficial knowledge.
If the second clause identifies a salient instance of the very favor announced first, the relation is detail after generality, making faṣl suitable. In a context listing distinct favors, the relationship could instead favor coordination.
Separate verbs alone do not decide the case. One must ask whether the latter clause specifies the same judgment or introduces an independently intended one.