> If Russia was able to create division, why are they so bad at it when it matters - now.
Just guessing: It is easier to create division, when you manipulate both sides. It is easier to manipulate both sides, if you genuinely do not care which side wins.
As an example, consider vaccination. Trolling only on the anti-vax side would be a rookie mistake. A few bad arguments get made, then they get debunked, for most people it's game over.
To do it properly, you must also have your trolls on the pro-vax side. Their purpose is to provide stupid arguments in favor of vaccination, so that anyone who remembers their high-school education will go like "wait a moment, this doesn't actually make sense". They will also make such nasty attacks on their opponents, that many decent people will go like "hey, I am technically on side of vaccination, but these guys are assholes; I would rather not be associated with them publicly". -- This creates the situation where you have lots of confused young people documenting the mistakes of the pro-vax side, and pointing out their horrible behavior. Much better (from the attacker's perspective) than if one side is merely wrong.
The important thing is that (to the attacker) it doesn't matter which side wins. The goal is to create conflict. If the pro-vax side wins, by doing something that will make the losing side mistrust and hate them forever, mission accomplished. A few more conflicts like this, and the society is ready for a civil war.
Now when the two sides are pro-Russia and anti-Russia, would you want to be the Russian troll assigned to write anti-Russian articles? It's a lose/lose situation, because if you are too good at doing your job, instead of a bonus you might actually get a bullet, if you boss starts suspecting that you actually mean it. But your boss is even more scared of his boss, which is why he will probably assing all trolls to write pro-Russian comments. The entire troll department will play it safe, but as a result they will be much less effective.