It's a simple thing, but many who write about propaganda don't seem to get it:

Propaganda can be divided into positioning and payload. Positioning is what is written to attract an audience. Payload is what the propagandist actually cares about.

There's very little payload. These farms aren't trying to "spread chaos" for its own sake. It's just a side effect of trying to gain an audience; clickbait media at its height was exactly the same.

Don't think the payload has anything to do with cultural issues. It's either narrow political stuff (I.e. getting people to believe Syrian rebels staged deadly attacks on themselves) or simply profit.