First of all, I doubt that Horowitz has 470 "Investigators." Maybe that is the approximate total staff; but, they have proven that their scope is limited to interviews with existing DoJ & FBI personnel in pursuit of VERY NARROW breaches of departmental procedures (Did she willingly pad her expense account etc.?) I believe the alternate version of 470 was Huber with around 500 investigators, not Horowitz; and Huber's scope is much, much wider.
Of course, the 470 could be both the 470th Mil Brigage and Huber's staff.