So, i have figured it out (i think)

[Tactician]

Unless the game is buying huge amount of fake downloads, i don't see why any manager would download the same game and delete it using different gmails. Even those who have more than one team, they download the game once and then login with a different Gmail. Google is very strict about these unusual activities and every smartphone even with the same brand and name still have a unique id and the number of downloads is based on those IDs.

Clone accounts can be created using different google accounts. The device stays the same, but the google account associated to it, and hence to Google Play, must be changed to access the clone account (unless I am mistaken as maybe you can access those directly like it is the case of those game accounts linked with Facebook) .

You can see some example of clones from the top 100 of associations itself. There is one user that even labelled them 1, 2 ,3... something like this.

It is against the rules of Google to have fake accounts and it is against the rule of Facebook to have fake accounts, and they have been taking action against that too (in the past, I had test accounts, and some of them got removed), but as you can see in the top 100, there are many still there and running.

There is another thing too. Lets say there have been 50 million downloads (unique users). You think there are 50 million different teams (active, semi active or abandoned)? Looks unrealistic.

There used to be a number count showing the amount of users of the game on the official game page (I have not checked if it is still there). The numbers there itself looks like they counted clone accounts too.

But I get your points though, and I won't disagree with that, and 50 million downloads, yes, but it is unlikely that are 50 million unique users for this game.