Other than the upvotes, most of those accounts have some arbitrary number tacked onto the end of their username.

It's not a useful distinction for determining whether someone is human or a bot. Reddit began suggesting usernames a few years ago and they all look like Randomword-Randomword-Randomnumber. I've read comment chains in the past where newer Reddit users were even unaware that they could choose their own account name. There just seems to be a new generation of people who can't even be assed to read the signup prompts and just keep clicking "OK" until they have a brand new Reddit account.