Trying them separate doesn't mean too much. Some jurisdictions don't like mutltiple CoD trials because then you are dealing with multiple defense attorneys. Sometimes when they all make confessions, it makes it difficult because you have to redact out of each statement, reference to the specific involvement of the others. Sometimes it is easier to turn one or two CoDs if you are after one or two most culpable who have not admitted guilt. Sometimes you say individual trials to try to get some plea offers and cooperation against the others. Mostly depends on evidence and degree of culpability...kind of strategy. Generally, you would like the fewest trials possible or the most pleas possible for judicial economy.