nice deck

it looks like it can fill up the field pretty quickly

-scapegoat

+mof/sinister serpent

maybe even magic reflector to protect gaia power.

This is a very good earth deck. I don't think i can improve on it much except that i personally would run Torrential Tribute it tends to be a little slow at times and if you have a lightning Vortex i think you should add it. Another card that would probably be good is Susuke Samurai even though it isn't an earth monster it can be comboed with book of moon; kind of similar to your combo with Nobleman of crossout, but it's not limited to just one card. It can also be very effective against Burner decks, so if you don't main deck it at least side deck it just in case. Another card that i find useful in any deck i make is Nobleman of Extermination because many people tend to keep copies of trap cards in their decks. Hope this helps.
Oh and thanks for the help with my deck if you have any more suggestions for my deck feel free to make them. My Rating for this deck is 9.6/10

Y Run Ceasefire And Noblemans In The Same Deck You Cant Nobleman The Monster After Playing Ceasefire Maybe Change It Out 4 Maybe A Magic Cylinder Cause Wheni Ran Cease Fire Most I Hit Someone With Was 2000 With Magic Cylinder Youll Do Bout The Same When They Attack And Youll B Able 2 Use Noblemans More.... Hit Me Back Tell Me What U Think