Here's the problem: That analysis you keep referencing infers transfer speeds from the file timestamps. While that analysis may be accurate, the rather dubious premise of the argument is that they represent the time the files were originally copied from the DNC servers, and since they could not have been copied that fast through the internet, the rather boneheaded conclusion is that they must have been copied by someone with direct local access to those DNC servers -- a mole, not a hacker. However, those timestamps are just the time of the last file copy, with no indication of where they were copied from or how many times they may have been copied before that. If the hacker downloaded the files to his computer through the internet and then copied them from his hard drive to a USB drive, or any of a multitude of other scenarios, all you'd see in the timestamps is the transfer speed of that last copy.
As for the "physical access to the servers" nonsense, it's a shame that senator didn't get around to explaining why they would need physical access. Comey said his people told him they had what they needed, which is true if they had the images the consultants took when they began the investigation. If the FBI had physical access, all they could do is take another image to analyze, but the earlier one would be better in case things had changed. (In fact, most of the servers were cloud-based, and the main feature of the cloud is that application servers are portable images that are independent of physical machines.)
Sorry, but these arguments do follow a familiar conspiracy theorizing pattern: Use a set of filtered and/or misrepresented facts to create a pseudo-mystery or pseudo-anomaly and then offer the conspiracy theory as the most plausible explanation.
