That field agents would be assigned only one segment of a investigation and then turn it in.
Still difficult to imagine that all agents could be kept in the dark on major political spying investigations.
They can easily be kept in the dark about it. 99% of agents knew little to nothing about what was happening on the top floor. This investigation was run by supervisors directly under the supervision of McCabe/Comey.
Remember what happened with Weiner’s laptop?
It was grabbed by McCabe’s hand-picked wonder agent (Peter) and it is likely that the initial agents handling the matter were told not to write anything about it as it was a “special investigation”. They did not do the search warrant on it - that was done out of McCabe’s office also so “they” never investigated anything... Strozk investigated it.