what about trying him at MLB and moving
No. It takes years for someone to learn the position. Melvin Jones is a better solution at MLB. I'm not worried about the LB core. Chavis will find a rotation to maximize the group.
Neal will be a beast DE. He has long arms, strength, and quickness. Beckwith can also take snaps at DE, while still learning to play OLB. DE is these players natural position and because of that it's much easier to put them in the game and let them rely on instincts.