Exposure to direct fire is a heavily weighted factor. Most likely Chavez received the Navy Cross because, as the driver of an uparmored HMMWV, he wasn't exposed to direct enemy fire....Meyer continiously exposed himself to direct fire while manning the turret and when dismounting to search for/retrieve the missing Soldiers/Marines.
All that being said, the military decoration system is highly subjective and it's very common to have people over rewarded for an act while others go unrewarded for the same thing....right place, right time, right boss, right witnesses, right command structure are all key components. As evidenced by Capt Swenson, who was there alongside Meyer for key parts of the battle, being completely left out of the decoration submissions.
I saw staff officers who sat in a command post for their entire tour come home with Bronze Stars while junior enlisted men who braved mine fields and enemy fire to disarm bombs came home with Letters of Appreciation or maybe an Achievement Medal.
