PrintMTGs own print spec cheat sheet says the same thing, and it also gives the pixel math people usually need: 750 x 1050 px at trim size for 300 PPI, and 825 x 1125 px if you include bleed
WB Humans, attrition (add green for more of both) UR Noncreature spells, but sometimes just instants & sorceries (add white to get extra value out of your Cycling noncreature spells) BG Mutate, Graveyard (add U for more Mutate support) RW Cycling, go wide (add B for more human tokens to go wide with) GU Mutate, goodstuff (add R for more good stuff?) To be honest, I havent felt this unsure about a formats archetypes in a while
Unless an opponents deck is tailored specifically to mill or burn the player, Threatening Roar is a great emergency card
Die-Cut A card that has been cut in a unique shape or design
Pull rates for the most rare of rare cards dont seem super great