Who would be the main signal caller if Lofton and Vilma were on the field at the same time? You think it would go back to Vilma calling plays on defense?
I'm not saying Lofton isn't smart... dont' get me wrong. But Vilma is one of the smartest players in the league. He will be calling the defense. But all of the defenders have the freedom to make sight adjustments... only Vilma will be the one actually calling any audibles (much like the QB on offense).