I understand the desire to take 4-6 units of 5 plague marines to max out on those special weapons but i just cannot do it. looking at the units at that size they just dont have the durability to survive any real punishment even with t5 and fnp. maybe in 5th it was workable but in this edition i dont see it as being that hard to shift 5 plague marines from an objective or to simply gun them down when able to. i like my units aroun7-8 simply for durability. those special weapons just need to have some cushion to prevent their destruction.