At the cost of using a slot three levels higher though. I guess that's a decent trade if you get 50 guys with one casting and you have plenty of level-9+ slots.remember that a lot of these spells can be affected by Chain Spell, greatly reducing the number of spells that need to be cast.
So how many of those could you cast on a dozen troops with one 20th-level Cleric and one 20th-level Wizard to do the casting (and no potions, scrolls, or wands)?Stoneskin, Bull's Strength, Cat's Grace, Endurance, Owl's Wisdom, Protection from Elements (one of each type, 2 on fire, lightening, and cold), Protection/Magic Circle Against/Auro of Alignment, True Seeing, Tenser's Transformations and Righteous Mights on fighters, Divine Power, Greater magic Weapon, Magic Vestaments, Barkskin, Deathward, Negative Energy Protection, Fireshield, Contingency, Chain Contingency, Delayed Heal, Haste, Mass Haste, Expeditious Retreat, Fly, Displacement, Blink, Booches of Shielding, Freedom of Movement, Spell Turning, Spell Resistance, ...

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.