@dataspot That was true before Dominaria, but now you are obligated to put lands closer to you and gy and exile adjacent to the library (in competitive and professional REL). Except in cases like @Oestrus pointed out, of course.
You can look here https://wpn.wizards.com/sites/wpn/files/attachements/mtg_mtr_27apr18_en.pdf in section 4.6 Game Layout.
About the graveyard order, the rules says:
3.14 Graveyard Order
In formats involving only cards from Urza’s Saga and later, players may change the order of their graveyard at
any time. A player may not change the order of an opponent’s graveyard.
So I believe in Eternal formats you cannot change the order of the gy even if you don't play cards like Shallow Grave. I could be wrong though, but that's what I understand of the rules.