These Oil counters do different things depending on the card, but if youre in those colors, you should be looking to spread Oil counters to as many of your cards as possible to maximise the effect they have on the game
Similar to Chatterfang, Squirrel General , this card will not give you double the amount of your tokens, but instead give you a 1/1 Citizen for each attacking creature you control, including your token creatures
Take a look: Weirdly, this particular rambling McNally has never seen a reprint, so any copy out there that you might see is forever just Creature Construct. As per official rulings, it is indeed an artifact, if you couldnt tell by the frame, the colorless casting cost or the general animated map-ness of it all
You can also pay one red mana to destroy an Artifact you control and one White mana to give it flying until the end of the turn