My speculative construct:
Joffe was an FBI informant at the time he started gathering the information about Alfa-Bank/Trump.
Isn’t it plausible that FBI resource and Dem/Hillary operative Joffe was acting on FBI orders, or at least with its knowledge, the entire time? Sussmann’s star turn was to re-introduce the cooked-up information so the FBI could have agents, not read into the operation, “investigate” it so the FBI could answer “yes” when “reporters” asked if there was such an investigation.
Will the Defense pursue the idea that Baker knew who Sussmann was working for because it was all part of an FBI operation? Er, no, even though they are in a position to know if it’s true.
I too wonder is the FIB weren’t knee deep in the construction of this narrative.