I was thinking... what if the reason that the Golden Earth Kingdom was NOT part of the Silver Moon Kingdom was because it was simply too much of a risk to go about a war. What I mean is what if KING Endymion(meaning past mamoru's father) was just as powerful as Queen Serenity, and if his Generals were each individually as powerful as an Inner Senshi.
We all know mamoru is at least relatively incompetent in the use of magic/the kinzuishou(at least while using it under his own will) however as far as I know it has been shown that the Kinzuishou is at least possibly as potentially powerful as the Ginzuishou if the fact that mamoru 'goes prince' so to speak when Usagi goes princess.
And in the case of the Generals they could have been theoretically connected to the earth's magical ley lines and since as far as we can tell earth is the only NATURAL life bearing planet in the Sol System it stands to reason that it would have more magical potential or rather it would have more Mana then the other planets.
While it could be argued that the moon kingdom could easily overpower the earth due to the outer senshi BUT the question is...
IS IT WORTH IT?
I mean is it really worth going to an all out war in which the enemy has the abilities to possibly cripple if not outright defeat you and whos to say that the planet itself could not theoretically become a weapon after all you would think that the terrans would be far more attuned to terras magic then the other planets and there senshi are if only because we EVOLVED on our planet and magic would have come inti being upon terra so at the very least we would have LOTS more practice with terras mana then the other planets.
Though I will admit to the fact that I know little of sailor moon as it has been about a decade since I first watched it and about 6 years since I read it buut yeah tell me what whar you think