Cube decks have less redundancy and so getting the dream of turn one Lackey into a Siege Gang has incredibly low odds
An EX-based deck is not only viable but often a popular 'meta' pick, because their strengths can beat down the opponent before their Pokmon cards can get revenge
Creatures (31) 3 Goblin Vandal 4 Goblin Recruiter 4 Goblin Matron 4 Goblin Lackey 2 Kiki-Jiki, Mirror Breaker 3 Goblin Warchief 1 Goblin Sharpshooter 4 Goblin Piledriver 1 Gempalm Incinerator 1 Siege-Gang Commander 3 Goblin Ringleader 1 Skirk Prospector Lands (18) Spells (11) Sideboard Once you stack your deck, every Ringleader will hit four more Goblins, meaning you can basically just draw whatever sixteen Goblins you want (and thats not even factoring in Goblin Matron)
While these arent super common, its important to understand that these costs cant be paid with any color of mana the same way generic costs can
I personally think this is where Streets of New Capenna falls
Summary Pick favorite lands to give deck synergy, consider theme options like full-art or promo lands