So your argument is that because of the game mechanic relations between D'Hara and Terran, this has to be considered a friendly merger? I don't think I like that. By that logic, two federated realms could break their federation (thus going to war) and then the next day one could surrender to the other and merge all their regions together. Bingo bango, it was an "unfriendly" realm merger, see? "Not a violation of the rule at all! It was clearly hostile because we were at war!"
I'm certain that's not what you meant to imply, but that is the implication I would take away from accepting your line of logic in this type of case, and for obvious reasons I don't care for it.
Have you heard of the term "necessary but not sufficient"?
Just because a realm merger
is friendly because the realms are allied or federated does not mean that it is automatically
not friendly if the realms are at war.