That part freaked me out because that was one of the ways I thought I could tell authentic from propaganda. I thought people in power didn't know how to blend in naturally to forums and their comments always stood out, but it looks like they do get it. Now I'm worried that my propaganda/astroturfing indicators don't work as well as I thought they did.

The article covers it quite well. The trolls generally don't really know what they're talking about and often don't make sense.

So if you ignore the nonsensical people you will ignore the trolls too. It's a pretty good rule to follow anyway.

At least in Guardian comments they make no sense, are intensely rude, and tend not to reply to comments. As you say it makes them very easy to spot.

From what I understand from the article, I think you are overestimating the quality of the arguments they bring forward.

You probably need constant vigilance to be aware how propaganda is being spread. Everyone is probably constantly trying new ways to spread it. Truth seems to be under attack in every direction.

Astroturfing is usually fairly easy to spot.

Of course, it can be difficult to tell those who are a bit fanatical about an issue from astroturfers, usually because the fanatical people are sourcing from blogs etc written by the astroturfers

I was scanned the comments looking for suspects. My best guess are: osipov, usaphp, and ibi7.

I made the same assessment, strongest on ibi7