"Let's rock."
♫Streak: You toss the flashbang over the cover, but even over an RCD it's hard to hear someone muttering. That is, assuming you had your com link on at the time. Nobody, not even the allies see the flashbang coming!
Nan: You pull out the Terminator's Terror and start laying waste to the cannon fodder, getting 6 kills until you notice a flashbang fly... when it was too late. You get fully blinded from the flashbang, including this turn, and as a result duck back into the cover, almost dropping your weapon and still blinded.
Kevin: Laying low behind the rock cover in the back lines, you open fire in burst rounds and pop some heads, getting 4 kills and wounding 2 enemies. Then all of a sudden you notice Mega duck, and a bright light and a loud sound hits your helmet. Due to your distance the flashbang wasn't as disorienting, but still blinded you for a second nonetheless. You're clear now.
The gunners get fully blinded except for two who managed to avoid the flashbang somehow. The entire enemy group gets disoriented however, and simply becomes sitting ducks!
(Pro Tip: Laser weapons, even those like the O-600 Laser Shotgun, generally have negligible dropoff due to their laser usage instead of bullets. This allows for medium-ranged strikes, especially since the specific shotgun's range is Medium and has a tight choke, meaning less bullet spread.)