2M “subscribed” users to a subreddit is about 10% or 200,000 daily viewers with about 1% of those commenting and 0.1% posting so 2,000 comments and 200 posts per day. Some subs will be more
or less but that’s the magnitudes we’re talking about.
The equivalent situation assuming mods review every comment would be a subreddit with 1 billion users. If mods are only reviewing reports which is some small percentage of comments then adjust accordingly.