I'm glad you said, "so called" leftists/tankies. This is from 2015 and they talk about mixing up the ideologies on purpose.

“Once we isolate key people, we look for people we know are in their upstream – people that they read posts from, but who themselves are less influential. We then either start flame wars with bots to derail the conversations that are influencing influential people, or else send off specific tasks for sockpuppets (changing this wording of an idea here; cause an ideological split there; etc).”

The goal is to keep opinions we don't want fragmented and from coalescing in to a single voice for long enough that the memes we do want can,...

https://archive.is/PoUMo