1st Elusiveness is the ability to slip tackles. Players with a high elusive rating when trying to be tackled is more likely to make the defender miss.
2nd Those are great ratings for a DT but does he have a high pursuit rating? Or does he have low speed, agility and/or acceleration? Those are also key ratings for a DT especially pursuit as it's the ability to get after the ball carrier. IMO low pursuit means no passion/ high pursuit equals a BEAST!
3rd Of course the man or zone coverage are important to the secondary players. If a player has a low zone rating then when in zone coverage he is more likely to not cover his area and leave receivers open. When in man if the defender has a low man coverage rating then he will most likely get beat constantly by the receiver.