Durai is calm, calculating, very cold and obviously very capable of making those around him respect him (through fear). Marcus was more like your classic con man: talked a good game, was far more personable and ruled with an iron fist because that's how he had to keep his power.
You're probably going to see aspects of both Marcus and Durai at Irwin. But it will be the cold, calculation of the military. There won't be the lead by instilling fear aspect I don't think.