5-cost Marco isnt the worst, hes a blocker that can be tough to remove from the field
Mendicant Core, Guidelight grows as you bring out more vehicles, and it lets you copy your vehicles when youre at max speed
Affinity Decks These decks want to cast and make a lot of smaller artifact creatures to enable actual affinity cost reductions, like for Urza, Chief Artificer (Magic's best affinity commander) or for other mana or card advantages, like for Inspirit, Flagship Vessel and Urza, Lord High Artificer
Foundation Breaker Ingot Chewer and Wispmare have been around for quite a long time, and theyve both seen a decent amount of play
It can easily become your primary mana source once you have a few Allies in play
Creature - Human Scout Sin, Unending Cataclysm Flying, trample As Sin enters, remove all counters from any number of artifacts, creatures, and enchantments