the balance of power would be maintained if Luffy, Kid, and Law become emperors and the yonko becomes the goko.
The marines are much stronger now than they've ever been due to the abolition of the shichibukai and the rise of the SSG. Whereas previously the shichibukai weren't fully loyal to the marines, they've now been replaced with a comparable but loyal force, the SSG.
As it stands, Marine HQ>Yonko
But if Luffy, Kid, and Law become emperors, then it would equal out. Because the supernova have surpassed Luffy, Kid, Law> Kaido and Linlin.
Anyways, I think Linlin's role as emperor is over. Her commanders were beaten, she was beaten, what's the point of her coming back as emperor?