Came back from the game with swarms. Seven people showed up, so I used three swarms (each representing a company of enemy soldiers) plus a commander (a controller [leader]) standing within one swarm and archer minions in an armored wagon with arrow slits. Not a single attack was made against the archers.
The barbarian had recently retrained away a close burst power that inflicted ongoing damage, so he was less of a factor in that battle. He also didn't use Phoenix Rage, which does ongoing damage. He attacked the commander.
The avenger focused on the commander, using a power to teleport the commander out of a swarm. The commander could teleport, but in his brief time away from the swarm, he took loads of damage from two strikers.
A fighter, played by a new player, used Come and Get It very effectively. It's a close burst attack, so... He didn't his damage aura so effectively though, due to being pushed around by the commander's abilities.
The shaman mainly did buffing and healing. So did the cleric. The cleric had less AoE than I had expected; he used Beacon of Hope, but that was more for the healing bonus than anything else.)
The paladin had a surprising array of close burst/blast powers. He used at least two that encounter, and I think he didn't use Radiant Delirium.
And we had a guest player. The player of the barbarian is also interested in the monk, so he had a Centered Breath monk of appropriate level lying around. The new player took this PC. I'd never seen a monk in actual combat before, but they have ... lots of AoE. Since each swarm represented 30 enemy soldiers, at one time he kicked 60 enemy soldiers in the butt. (Well, not really, but it seemed like that.) He could also slide groups of enemies around.
They turned out to be less grindy than I'd expected, even though they were also soldiers. This was due to some really cool uses of forced movement, and also not making all the enemies swarms, so people without AoE could focus on them.