Five mana asks the format to be slow enough that a turn-five haymaker still matters, and TMT obliges. The medium-speed common bottom (2/3s and 3/2s for three, modest aggressive starts) means a 7/5 lands into a board that cannot race it and forces a removal spell that black and white can usually find but red and green often cannot. The pick is P1P2 to P1P4 for a base-red drafter committed to Alliance, and it slides several picks lower the moment red stops being the base.
The home is Mono-Red or RW Alliance, where the trigger count is the entire reason to pay the overcost. The hybrid Mechanized Ninja Cavalry and the cheap red 2/2s chain into Slash to drop an opponent four or six in a turn while the board widens underneath. RW adds equipment: Bespoke Bō and Novel Nunchaku turn the 2/2 token stream into a real clock instead of chump fodder. UR Sneak wants this less than the rate suggests; that deck is built around individual evasive bodies, not entry-trigger density, and a five-mana top end that needs follow-up creatures pulls against the curve UR runs. BG Food has no use for it.
The punisher is Grounded for Life. It gets cheaper against a tapped creature, so the moment Slash attacks, white answers it for two mana and the engine collapses before the second token enters. Stomped by the Foot does the same work on a wider window. The standing concern that five mana leaves the curve thin is real as a ceiling, but it underweights the attack trigger: the 7/5 manufactures its own Alliance fuel one swing at a time, which is exactly the failsafe the body is paying for. Maindeck in any red deck that drafted three or more Alliance enablers.

