It would be difficult to turn top leadership in a group because they are probably the most devoted. It's likely easier to start from the bottom. The guy that always has time to attend meetings or participate or throw in some cash (the ideal member) is going to quickly rise in the ranks. The guy with 5 kids at home and is too busy with work is not going to be an given leadership roles. The guy that only needs a fig leaf of a job is going to have plenty of time to "help" the group plan and execute tasks. He's always going to have some connect that can come through to move things forward. A fed isn't going to be the one to suggest crimes but they will certainly be there at every moment to eagerly help move it forward.