My first few games of 8th had lots and lots of firewarriors with darkstrider and a fireblade holding down the center of the field. If they got charged, EVERYONE could pull out and fire. I had several units clumped together so I frequently had multiple sqauds tied up but only 1 or 2 with any actual casualties so getting the full squads out was generally invaluable. I like the tactic but when you use it with breachers in a fish off by themselves you tend to get more use out of the structural analyzer than the fighting retreat and even then the analyzer is only super useful against t4 bringing them down to t3 so you wound on 2's with the 5" profile, or bringing their t6 to t5 so you go from 4's to 3's or attempting to punch down heavier armor at t7 to t6 so you can wound on 4's. Not super useful but it has its place.