You dont need to believe there are thousands of US sleeper agents out there to believe the case against Assange is dodgy as shit. Nor do you have to believe he is a lovely man, and the sole hero of wikileaks.
That the US would like to fuck him over in any way they can is surely undeniable, and that they can exert influence over foreign governments and legal processes to do so is, surely again, a simple statement of fact.It is highly unlikely that anyone other than Assange would have faced any charges for the alleged offences as stated, certainly not to the extent of seeking extradition proceedings.
Thus, Assange's fear of persecution is well-founded - ie, 'genuine' and objectively reasonable.