On at least two occasions, Poland appointed as kings, rulers of other countries. Once was in the fourteenth century, when the king was Lajos of Hungary. Another was in the eighteenth century when the king was Augustus the Strong of Saxony.
In NEITHER case did Poland merge with the king's other country, so these "personal unions" did not end by uniting the two countries. On the other hand, Poland did form a partnership with Lithuania by marrying off its "king," Jadwiga (Lajos' daughter), to Jogaila, Lithuania's Grand Duke (king), although the partnership wasn't fully consummated until the mid-16th century (a century and half later.)
How would Lajos, for instance, have ruled Poland, while personally governing Hungary from Budapest. Did he appoint a viceroy? Or did he have a council of Polish nobles reporting "loosely" to him while they mostly did what they pleased?
Did Poland gain any advantage from having these kings with commitments elsewhere? Did the country do better or worse with Lajos, Augustus (and others, if applicable), in comparison with kings that did not have these conflicts of interest?
And are the two sets of questions in the two paragraphs related, that is, does HOW this kind of government worked affect HOW WELL the government worked?