«وَالْجَامِعُ بَيْنَهُمَا أَيْ بَيْنَ الْجُمْلَتَيْنِ»
The unifying relation is between the two, that is, between the two clauses.
What needs to be linked are two complete predications. The subjects and predicates of each clause all contribute to how their relationship is understood.
The four constituents need not match individually. The central question is whether there is a fitting reason to present the two judgments together.