It seems to be agreed that the laser grenadiers need fixing. Yes, they are the **** in Dust Tactics; not so much in Warfare. And, they are dead ringers for the Red Skull's troops ("Hail Hydra!"), which makes them cool.
Here's my suggestion: Instead of giving the regular laser-werfer the 'laser' designation, simply double the amount of attack dice vs. troops. This makes them the dead shooty gits that they are in Tactics; you can rationalize it as lasers doing more damage more easily to mere flesh. The schwerer laser-werfer gets no changes; it's still real deadly against armor. The regular lasers retain their normal attack vs. armor, and also lose the 'laser' ability.