Hillary really was very secretive, and only told her staff what they needed to know.
Bill was the main quid pro quo guy cash collection guy working out in the field.
Most of the staff knew pieces of the puzzle but did not fully understand all the pieces.
Make no mistake—Podesta, Mook etal were part of the coverup and were actively engaged in obstruction of justice and obstruction of a Congressional investigation.
However, the record is clear (imho) that there was a period of time when they did not know about the Clinton private email system and its use as a mechanism of the Clinton Foundation pay for play scheme.