For this to work, Congress must have information from all the sources before the two are subpoenaed or ordered to comply.
I hope this is how it is proceeding. That said Wray, Rosenstein and Sessions cant be trusted nor anyone working for them in a close position.
That's the crux of the problem, isn't it?
Who will mind the minders?
The keepers of the law are the breakers of the law.
If laws worked many of those same people would be up on charges or already in prison.
Along with Eric Holder, Loretta Lynch, Lois Lerner, Hillary, Bill, Huma, Washerwoman-Shultz, Comey, Obama, Kerry, and on and on.....
Instead they single out a few small fish (like Flynn) and fry them as a warning to others to not challenge or defy our rulers.