In that case, why does the game continue to recognize realms that lose their last city? I'm not talking about the need for manual deletion but shouldn't the game automatically force all regions and nobles of the realm rogue then once they lose their last city because the realm is dead under your interpretation?
Yet, the game continues to recognize the realm as functioning. Militia can still be recruited and armies still utilized. In addition, all RP I have seen indicates that the playerbase believes a realm to still exist so long as it holds regions and nobles both.
You are correct on the technical aspects of this statement, but you are missing what I believe to be the intent of the rule. It is intended to prevent realms from peacefully agreeing to band together to form superpowers, as this stifles conflict. If two realms have been at war and one of them is eventually beaten down and surrenders, it is acceptable for that realm to agree to terms that involve its regions being transferred away, within the limits of game mechanics. It's the two realms at peace merging together that we're trying to prevent. You can point out that Tara and Coria are at peace, but the important element in this case is that Coria has been effectively destroyed; with no capital, the realm is doomed. Its nobles cannot recruit or cash bonds, and its regions are slowly going rogue with no capital support. Their decision as a defeated realm to join Tara is acceptable within the spirit of the realm merger rule, or at least that is my interpretation.
Seeing as I'm rather close to this case (being a noble of Silnaria) I will recuse myself from voting on the outcome.
