From a big-picture perspective, there are three milestones the players are trying to hit
Do skeletons fit into zombie decks
Instead, I can focus on the flavour
Combining that beloved haste keyword with a critical cost reduction of Goblin spells you play by one colorless mana, Goblin Warchief immediately vaulted Goblins into the limelight of excellence in Standard, and this card remains a potent threat for kindred Goblin decks in Commander
In short, there are a ton of interconnected decisions that need to be made in a limited amount of time and often on imperfect information, and every single one you get wrong will measurably reduce your chances of winning the game
are ones that enable the deck's core theme of manifest dread, which places cards face down on the table so your opponents don't know what's underneath