From what I remembered, there have been talks within both the Kingdom and Empire about having multiple sub-factions within the main factions of Empire and Kingdom.
So in theory, two things can happen.
The first being that the sub-factions within the faction actually mostly retain that same faction and continue without their leaders.
The second, which is the more likely part, is that each faction would claim successorship and go right ahead to fight a civil war among themselves.
Unfortunately, I had asked Lauri some time back on whether there's a "Script" in place to instigate the fall of either faction and he said it's going to be based on the player base.
References:
But ngl, your concern is still waranted, Stanky.
