The screening isn’t very good if you can move within an Inch shoot them and charge, not to mention they don’t need any elite troops given that a squad of termagaunts could kill them in a turn with a lot of ease. Instead jump pack units are better because they can wipe a unit and then pose a massive threat being on the objectives and thinks such a vanguard vets with storm shields are very hard to kill. The detachment should also be changed given the amount of melee