Wild speculation? Jr. tweeted out his own emails showing that he thought he was meeting with a Russian government official to get dirt on Hillary. Manafort handed over campaign data to Kilimnik while still part of the campaign. Even if it's somehow true that they were ultimately too incompetent to pull it off, there was clearly active intent to conspire with the Russian government.
Beyond that though, Barr is simply wrong that it doesn't count if they were technically private Russian citizens and not Russian government officials.