فتفصيل المسند إليه مع اختصار
Thus the subject is set out in detail while keeping expression concise.
One predicate may apply to several people. Coordination states the additional participants without repeating the complete verb phrase each time. “جاءني زيد وعمرو” communicates the arrival of both persons more compactly than two fully repeated clauses.
Detail lies in naming the participants; economy lies in sharing the predicate. Separate clauses become preferable when the speaker intends different circumstances or independent emphasis for each arrival.
Coordination is rhetorically successful when its brevity does not conceal a distinction relevant to the listener.