I'm not complaining. I think it's great that Astartes are horrifically good, even when unarmed. Although I wouldn't call the combat blade a 'knife' really, as I think that the stats are more in line with swords from the other games.
[i'd rather go against the martial arts master myself. Because he's not going to do any more to you than he wants to (and he probably doesn't want to kill you and go to jail for 15 years), whereas the punk with the knife stands a good chance murdering you by accident!]

Pretty extreme but we got good results.