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.
By that logic, when the code is working properly, it would be
impossible to accomplish an illegal realm merger, and thus the rule against them would be unnecessary.
This is not the case. The rule is not, "You may not press a button to peacefully bring the last region of a realm into another realm." The rule is, "You may not peacefully merge two realms."
It
should be obvious that, when the code is working properly, it is
always necessary to either declare war to conquer the capital (or other last region), or somehow induce it to revolt to your realm.
There is some validity in the question of whether this is an illegal realm merger versus a surrender. There is
absolutely no validity in the argument that "we have to declare war to conquer the last region, so it can't be a peaceful realm merger," and you should frankly know better than that, Dustin.