You need to factor in HP pools to these equations also, so:
AoE - 10'000hp divide 106.6 dps per mob = 93.8 seconds.
ST - **I must stress here these values in this thread is a very vague rotation used to accomplish this DPS value. ST would be more like in the 320+ range as per this post
here**
10'000hp divide 350 dps per mob = 28.5 seconds.
x 2 mobs = 57
x 3 mobs = 85.5
x 4 mobs = 114 = Break point at which AoEing becomes viable.
5 mobs minimum per AoE is efficient and effective, any less is a waste of time when factoring in the eDPS incoming on a Tank is more effectively mitigated with less mobs in a pack. It then becomes about how well geared the tank is or how well they play.
Honestly, any content worth a damn is single target based anyway, unless people claim WP speed runs as content that matters, then Summoners rule that roost anyway for AoE damage.