The key to undermining those fringe groups is not scrutinizing their links to Russia or dignifying their addiction to Russian nonsense as if the cheap disinformation that they spew is just "too powerful", but to see what valid grievances they use to grow and address them. A fault line that doesn't exist can't be exploited by Russian trolls.
This assumes there are valid grievances. I see mainly raging narcissists whose self worth stems from believing something else then 'the mainstream' and geniune crazies.
Looking back at some of their statements it went something like:
-Pre-invasion: "Only NATO warmongers think Russia will invade"
-Invasion day: "This is not agression but a logical response to NATO agression and nazis"
-Day 1: "Look at the Ukies collapse, this is faster then the Afghan army lol"
-Day 30: "Despite what the NATO propaganda claims this is all according to plan and the whole Ukie army is about to be caught in a cauldron and destroyed"
-Future: "NATO may want nothing more then the fighting to continue but Russia, having destroyed the targets it wanted to, will pull back after a job well done"
No attempt is made to be consistent, it's all just the opposite of what the State Department says.