Let's go back and review the Republican 2016 primary... going into it, the presumptive lead candidate and party choice was... Jeb Bush.
He turned out to be a washout, a bureaucrat with little charisma or appeal, and a sitting duck for Trump's 'low energy' label. Jeb did poorly in the first primary, and the next, and the next... never did get going. Just not presidential material. (arguably, neither Trump nor Clinton was presidential material, but in Jeb's case, it was painfully obvious)
From that point on, there was quite a gallery. The tea party put forth right leaning/puritan Ted Cruz. The mainstream (what little there is) had John Kasich. A wildcard policy wonk was Marco Rubio. Plus Ben Carson... and there were a few others like Carly Fiorina, fresh off running HP into the ground, and another tea partier, Rick Santorum, that never seemed to gain any support.
Plus Donald Trump, who had made a small bid in 2012 garnering a few percentage points, making what was thought to be another small bid in 2016. No one took him seriously, until he started winning primaries.
Out of all of those candidates, only one tapped into what the electorate was really concerned about... jobs for US citizens. The rest of the Republican candidates seemed to be following either the tea party line (obstruct... oops, we're in the majority now, do we obstruct ourselves?) or squabble amongst themselves over trivial issues.
Cruz became the school principal... as if we're going to elect what we tried to avoid in school. Kasich... just never seemed to gain any traction. Pity, he would have been a good centrist choice, had an admirable record of working across party lines to achieve a goal. Rubio tried to play Trump's bluster game and failed badly. Carson kept making more and more wacky statements.
The nomination went to the person who placed an emphasis on revitalizing US industry and creating more jobs, not on preaching dogma.
Unless one wants to suggest that the Russians guided Trump's primary campaign, which is unlikely as what Trump campaigned on is what he had been saying in years previous, it is safe to say that the Russians had no impact at all on the Republican nomination.
As for the Russians having any impact on the main election, take a moment out and review this NYT article that shows many of those Russian created ads. They appear to be nothing more than typical fringe group stuff that would appeal only to people whose mind was already made up. Hardly the sort of thing that would change anyone's vote.
Note that many of those Russian ads were promoting Bernie Sanders... maybe they were actually trying to help us...