That Homeland clip about the office full of sockpuppets with talking points...
I've no idea how true that is for the US (it might well be), but it's definitely true for Russia. They have whole office blocks of sockpuppets, with folders of talking points, working in English.
Salutin' Putin: inside a Russian troll house
www.theguardian.com/world/2015/apr/02/putin-kremlin-inside-russian-troll-house
Which, interestingly, matches the behaviour of some of the Trumpettes we saw on here, and the obvious only-here-for-Brexit campaigners.
It was particularly obvious when something new came up, eg when Sarah Wollaston MP said she could no longer support the Brexit campaign because of their misleading NHS claims.
They went terribly quiet. Didn't express an opinion. We joked at the time they were waiting for new orders...
China too have office blocks of hackers, though I'm not sure whether they do social media propaganda as well as their well-known mass hacking efforts (for industrial info as well as for more obvious disruption).