Size is a poor indicator. 11 of me could take down a large but slow grazing animal. But a smaller predator would jack up 11 unarmed me's.
Maybe we could all gnaw on a cow long enough to bring it down.
With no weapons, I find this unlikely. The buffalo would pulverize you one by one and there's not much the rest of you could do to harm it. If you crowd together it could trample you all in one go.
This reminds me of a rhetorical question that I'll modify:
Would you rather fight a big animal with 10 clones, or fight a big clone with 10 animals?
For your question, if we are sticking to size alone, I think me, myself, and 10 of myself could take down an elephant. It doesn't appear we need to kill it (thanks!), so tripping is the name of the game. Everyone grab a leg!
You don't need the clones. You just need to be able to stay out of the animals reach. We are the only animals capable of running for days at a time. We're not the fastest, burn motion is very energy conservative.
You could hurry most prey to chase you run away from it and just keep doing it until the prey died of exhaustion. Of course you'd have to be in top physical condition which mean or any of my clones would be but the training will be part of the requirement.