Applying identical keyframes to identical objects w/variation
I would use a particle engine of some kind to do this.

You set up the Emitter to start from the same position as your torch (in a layer behind it).

You set your particles to look like the ball.

You emit them at an appropriate rate, and use air or wind adjustments to "blow" them across the screen.

After Effects has a built in particle engine called Particle World

https://helpx.adobe.com/after-effects/using/simulation-effects.html

Or you could use Particular from Trapcode

Screen shots below showing roughly how you could do it in Particle World: