The joining of Sun Hall Duchy to LN may not be a bug exploit, however it is the intent that one needs to look at and if the intent is in line with the spirit of the game.
I have understood merger to imply that there is an understanding between the leadership of two realms that one will simply give up and be subsumed by the other. We've frowned on this in part because it potentially shortchanges the wishes of other players in the realm that's dying.
All but two regions ended up moving to another realm. There was really no opportunity for the other nobles of Solaria to choose if they wanted to join LN or not.
Basically it boils down to this.
"If it quacks like a duck, and it waddles like a duck... get your shotgun out 'cause it's duck hunting time"
