I still have questions whether this was a grand conspiracy or just a couple of coincidental pieces that were put together later on
I think it started out slow and then ramped up once it was likely Trump was going to win the nomination. Manafort showing up on team Trump was like winning the lottery. Trump probably didn’t know much about Manafort’s activities, but democratic operatives at FBI/DOJ/CIA did. I suspect they were going to use Manafort as an October surprise, but word of his Ukrainian financial ties came out prematurely and Trump fired him. At the time of Manafort firing we know Papadopolis ran across the Australian Ambassador Downer at a London bar in May. The Trump Tower meeting with the Russian lawyer lady was mid July. When Manafort gets fired, Harry Reid goes nuts and fires off a Russia collusion letter to Comey 10 days later after a meeting with Brennan. I doubt Reid was directly involved, but served a purpose like McCain and the dossier release.
I believe Manafort was put in there by the Dems to ensure Trump got the nomination. Remember, he was the one they thought easiest to beat.
From what I’ve read, Manafort came to Trump saying he could help. Manafort has been doing the GOP convention gig for decades. His speciality was supposedly keeping delegates inline.