Triple red at five mana on a sorcery that does nothing against half the decks in the format is not a maindeck card, and TMT does not bend that math. The artifact density at common is real but uneven: Bespoke Bō and Novel Nunchaku show up, Food tokens drift in from the BG and Mardu pizza shells, and the occasional Sneak payoff carries an artifact rider. None of that adds up to a board state where untapping and hasting every artifact your opponents control swings a game. Worse, the untap clause does most of nothing in this set: equipment does not tap to apply its bonus, and stealing an equipment for a turn does not pull it off their creature or attach it to yours, since you would still owe the equip cost. The clause earns its keep only against mana rocks and tap-to-activate artifacts, which TMT commons rarely supply in number.
The sideboard case exists and is narrow. UR Sneak builds lean on artifact threats more than other pairs, and that is the one matchup where untapping a couple of activated artifacts can buy a real turn. Even there the triple-red cost gates it out of anything not base-red with real commitment, and base-red decks want Bot Bashing Time and Shredder's Revenge ahead of a conditional swing that whiffs game one.
Pick it P3 wheel or later, a flex sideboard slot for mono-red drafters who expect a heavy artifact UR opponent and can spare the room. For everyone else it is a binder card. The fantasy of seizing a Turtle's arsenal is loud; the format does not assemble that board often enough to maindeck the answer to it.

