Who said anything about war? They'd be very effective against a MAGA rally. The deep state scum would just declare that it's an insurrection and bomb away.
You have a healthy imagination.
However these things would be useless vs an indoor venue. They are light bomblets that are unlikely to penetrate most roofs and explode among the crowd.
And anyway, after just one volley it will no longer be a matter of rallies, but guerilla war. So not much ammo likely to be used.