In the web comic Erfworld, the spell “Summon Perfect Warlord” summons the perfect warlord, who may not be perfect by the standards of Erfworlders, but possesses the skills needed to accomplish whatever they were summoned for (along with, it seems, an associated Fate). The spell isn’t unknown to the denizens of the Magic Kingdom, since it was cast at least twice by different casters, so it’s probably known that it has been successful before: Judy Gale, for example, successfully performed the task for which she was summoned, croaking the Overladies of Easteros and Westeregg.
Even taking this into account, the cost of the spell is 500,000 Shmuckers, which might deter the average side from employing it in spite of its usefulness.
However, the spell also brings magical items with it. Parson’s calculator watch, for example, could be put in a bracer, creating a Mathamancy item whose value was calculated at 500,000 Shmuckers (the price of the SPW spell). He also came with the Sword of Ruthlessness, which might also have been a very valuable item, and the 3D glasses (which would be of limited value to any Erfworld unit). Judy Gale came with her own items, which were presumably similarly valuable.
Despite all these benefits, we’ve only seen it used twice: once in the main comic, and once by a rather ancient side.
Given that the spell more than pays for itself by bringing valuable magical items, not to mention a valuable warlord, why is it not more popular?