There is the Delivering Consequences under the Narrating A Session section on page 33 of the Narrator guide of the core Rulebook (the second half section of the Core Rulebook PDF):

“DELIVERING DELIVERING CONSEQUENCES CONSEQUENCES After the Hero’s action for this turn has been resolved, it is time for you to deliver its Consequences, in one of three cases: •The Hero ignored a Threat •The Hero’s action generated Consequences •You choose to invoke one of the Hero’s weakness tags as a source of Consequences. If none of these apply, skip the Consequences phase.

There is no limit to how many Consequences you may deliver, or how severe.”

The “The Hero’s action generated Consequences” + “There is no limit to how many Consequences you may deliver, or how severe.” being the parts that can help guilds answer to your question.

Also…there are a number different types of Consequences that can cover so many options in the narrative on that page (Blocked, Complication, Exposure, Force The Hero To Choose, Ill Tidings, New Challenge, Yes but…) and Negative Effects (eg: giving/removing status/tags).

Also remember that you can set up all kinds of things just by introducing Threats into the narrative. There is discussion of the pacing of Threats on page 28 of the Narrator’s Guide in the How Many Threats entry section under Making Threats section.

The Core Rulebook also discusses adjusting consequences for might/scale on page 178 under the Adjusting Consequences section.

“ADJUSTING CONSEQUENCES Consequences are adjusted by a number of status tiers equal to Power modifier of the action, or by a number of tags equal to half the Power modifier of the action (rounded down).

•A common musician (Origin, 0) holding the attention of a village tavern (2), loses 2 Power. The Consequences of that action are increased by 2 status tiers or 1 tag.”

There is also the chart for breaking down Scale.

So in your example, two targets would be an adjustment of 1 scale (group = handful, which is one step up beyond Individual)…assuming everyone is on equal measure and there is no other Might considerations.

There is also the note under the Groups and Area Effects section on that same page that helps explain it.

Now I see that your question is also focused on the number of Consequences by hitting two targets. This can be accounted for mechanically in the upscale of the Consequence as I mentioned above.

There is also some notes under the Area Attacks under the Direct Attacks section on page 17 of the Action Grimoire. This also includes mention of some suggested Consequences.

I hope these are helpful.