I don't feel this is a realm merger for the simple fact that the nobles of Terran aren't going to be part of D'hara. Even with those that switched over aren't going to stay long. The fact that we aren't staying makes it a non merger. Alaster is a die hard Astroist. He serves the church before the realm.
In this case the realm was part of the church and it came down to losing it to enemies of the church or giving it to those who are at least friendly to the church.
weeks before the war broke out this had been discussed with the Theocratic Rulers, D'hara's Ruler, other trusted nobles and most of Terran. Not once was it brought up that this might be a realm merger. My understanding of the rules was that this would not be a merger.
My other case should have no bearing on this one as the situations aren't related.
As I understand it, the only thing that made the Solaria/Luria Merger not legitamate is that there was a bug that allowed him to take the capitol with him. In this case, the capitol has not changed hands. If D'hara wants it they are going to have to occupy the city.
