In the case of the former, its because the best choices vary not only by color identity, but often by specific deck building limitations: Seismic Assault and many other red effects want you to play an extra-high land count, while a black deck with reanimation and Tortured Existence obviously cares about discarding creatures
Since things might get a bit more nerdy, and I completely understand that not everyone wants to delve into this level of detail, below, Ive included an excellent Solopress video that shortly explains the entire printing process in just 2 minutes
Splinter, the Mentor Splinter, the Mentor ensures your nontoken creatures result in at least a fresh artifact token, and the partner capability makes it a joy to build around
Refined decks will try to account for randomness created by the initial shuffling of the deck, as well as the opponent's actions, by using complementary and preferably efficient cards
Subterror Behemoth Stalagmo X EARTH Level 10 [ RockFlipEffect ] ATK 2800 DEF 2100 FLIP: You can discard 1 "Subterror" monster, and if you do, draw 2 cards
