I think it also depends on their development rating. I bet Dez has either Superstar or quick for his development, while the other guys could just have normal for their development.
So far I like the franchise mode. In the second year, got a couple studs at RT and LG in the 4th and 5th round and the offensive line is dominant in pass blocking. I've been developing Vaughan, and now he's a 76 overall, and might be good enough to start the 16 season. Heath is an 84 overall, after being a backup the 14-15 season and Wilcox is an 87 overall.
Still can't run worth a damn, opposing linebackers have perfect awareness of the run and usually a lineman will run right past them to block the safety 20 yards up field.
And then it's impossible to stop the run on All-Madden. Seems like the linebackers are too hesitant and by the time they react, the RB is already at full speed blowing past them.