IF BFG:R sees many fans? I am not sure. I think people will pick the parts they like.
"You mean, if I shoot my awesome new better rules Retribution at this Sword squad, I can only kill one? All that firepower for ONE?!"
SPLIT WEAPON FIRE!
So 3 shots on escort 1, next 3 on nr 2 etc etc
Tag/aid,
you can split fire, so you can simulate 'spill-over' you just have to think about it.
But in that light, as you can split, spill over would make only a very slight difference.
Why?
Because of blastmarkers in between. With spillover the 2nd escort has no protection from blastmarkers. Without spillover it has.
So, a very small increase in protection only!
But staggered dice rolls instead of one roll with many dice.