You could have people dm you the memes and you could post them in a thread so nobody knows who made the memes that way people are voting for the memes and not their favorite accounts. I don't love this idea really because I feel like the competition itself might have less engagement because people arent posting and zapping and generally having a good time and I guess each account could repost their meme and get the engagement of their followers. Idk. Its tough. Not sure there's a great solution.