You could make a dungeon with different paths that are for different strategies.

Path one for singe target DPS: when most of your party is manly for single target dps. A few mobs would be here but have a lot of HP.
Path two for aoe DPS: when your party can dish out a lot of aoe. Huge amount of mobs but with less HP.

And maybe - Path for leveling: More mobs than the other paths, a bit easier maybe but give more exp?