Tinker doesnt even need a second card to be absurd, although frequently it was combined with Time Walk to great effect since all you need to do is untap
The low casting cost and seductive wording of that ability has tempted many players to try this out, only to realize the brutal mathematics involved
It would be only be the seventh most expensive deck in our current Standard format $200 less expensive than Jeskai Black, GW Megamorph, or Five Color Bring to Light
Someone always pushes the envelope and most groups have a player or two who are either less experienced or less focused on winning, but parity is still a good thing to keep in the back of your mind
give an opponent some dorky blockers, get yourself a land that taps for 3 mana every turn
"Oversize cards" is not a "set" by the usual Magic definition, but I'd guess your online store categorizes them that way to make it clearer to customers they're buying an abnormal card