I don't know about LVE anymore. He has the ideal size and had ideal speed to play MLB. He just was never able to stack and shed, and dropped his head when taking on 330lb guards (inevitable injuries thereafter). I don't know if he just didn't get the required ability to use leverage inside, or didn't get the strength. He started running around blocks instead of stopping the "hole" and shedding so he could make plays.
Micah is an OLB, and pass rusher, and flow to the ball type guy. Keep him clean and he will be very good. He can play a little OLB in the 3-4 and Will in the 4-3 and move around in the nickel.
Neal is the hybrid safety/Lb used to cover, but can still stop the run. Cox I assume will be used much like Neal, at least from what I have heard of his ability as a coverage LB.
I am assuming that Neal/Cox will hold down the Sam and ILB and be fairly good in nickel coverage.
IMO, LVE needs to develop quickly, or Dallas needs to get a stud MLB that can stack and shed as well as cover the middle zone or Dallas needs to be looking for one to draft highly in the next draft.
MLB is one weakness that Dallas needs to look to improve on if they want to get to the elite level.
I haven't seen enough of Gifford or Bernard to have a real opinion on them yet due to injuries and lack of playing time.