So why do you think Durham wants to introduce it as evidence? He must have a motive for doing.
A chain of multiple inferences sometimes must be presented to make a criminal case. A good fefense lawyer will attack each inference individually and by whatever argument possible, the idea being that if at least one link can be broken, the whole chain fails.
The motive is ensnare and strike fear into others involved who might turn state’s evidence or cut deals. By keeping the focus on a single defendent it makes discovery the route to bring others up on charges. The only purpose is to make this take longer. The longer one trial the more time criminals have to cover their tracks or kill those who would harm the Obama-Clinton-DNC RICO.