Noise you still don't get it, it was never about proving collusion, the whole collusion was angle introduced by Trump and the right wing media he owns. Nowhere in the authorizing mandate or anything since is the word collusion even mentioned, collusion doesn't even imply a criminal act and it is next to impossible to prove, did you really think Mueller was appointed to look for an act that isn't a crime nor worth prosecuting?
Coordination or connection between Russian efforts and the Trump campaign was that which was to be examined, and Manaford, the campaign manager, certainly falls under that along with the infamous Junior meetings to cite a few examples.
