This case will be easy to prove.
1. Did he and/or his wife take money from the shell corporation. Yes
2. Did he know the shell corporation was being used to launder the money from the Wall charity? Feds either have the goods via texts, paper trails etc or they dont. Sounds like his texts give it away.
3. Someone will rat the others out. My guess is that guy who ratted on his shylock will be one to seek a deal. Bannon ratting out lesser people will not be sufficient for the Feds. He would have to roll on someone like Mercer, Guo, or Trump
As you've seen with the Flynn persecution, the corrupt system will just do what it wants, the law be damned.
Otherwise, Rapin Bill Clinton would have done a stretch for perjury.