Well 5-2 is actually a prefect defense in person if you have the right people, if you drop the LB's back into zone coverage in the middle of the field, also if you have high rated DB's, being able to run 4 high rated DB's should be able to hold coverage easily. The seahawks and broncos played a lot of 5-2 defense this year because of the elite DB's they have and solid athletic LB's who could drop back into coverage and close in on a run/dump pass fast. Also the 5 up front, you usually have 3 huge power guys in the middle clogging up space, with 2 DE's playing on the outside of the tackles who have speed to make chaos on the outside.