From what little I understand that little fan is only for cooling of the VRM's and, iirc, it does a pretty decent job that was noted in a review of the cooler I once watched. But it was mentioned in the review that typically VRM's are running within their design spec and as long as that is the case having them any cooler doesn't make much of a difference.
The lead for the rad fans, well the connector, can be seen entering into the hose towards the top corner near the rad. All three of my fans are daisy chained to that single connector. The fans seem fine for me and my 420mm rad.
I do not notice any noise from that little fan, then again I have the case side on and it is not sat that close to me.