Why subscriber count is not enough
The wrong question is “how big is the channel?” The better question is “how likely is this creator to make content that matters to this game's audience?”
Start with genre fit. A creator who repeatedly covers comparable games has already demonstrated audience permission. Then look at recent average views rather than the biggest video on the channel.
Format fit matters just as much. A tactics game may need long-form explanation; a chaotic co-op game may work through reactions. The creator's normal format should make the game easier to show, not harder.
Finally, add reachability and responsiveness. A perfect theoretical creator with no contact route and no history of covering unknown indies may deserve lower outreach priority than a smaller creator who requested a key themselves.