Take this post for example: https://www.reddit.com/r/northernireland/comments/1ll6ocg/see_it_say_it_censored_kneecap_is_not_the_story/
Speaking from experience, people in Ireland are overwhelmingly pro-palestine.
There is this user in the comments: https://www.reddit.com/user/EntireCourage308/
Its a nearly year-old account, it started posting about a month ago, it made some innoculous posts, then pivoted to posting far-right misinformation in the r/northernireland subreddit.
There’s loads of other accounts just like it.
The problem is, unlike most people realize, astroturfing is rarely sourced from shill accounts like it used to be. Nor are high-karma accounts being purchased.
The issue is bots and shill accounts manipulate vote counts of posts/comments with certain positions. So, you don’t tell the difference, unless you find a way to track who is voting on Reddit content.