I often read:
When playing against Rebel Saboteurs, don't bunch up. Elite Saboteurs have Blast 2 and can trigger the same surge ability twice. That sometimes means blast 4 for adjacent units.
This is Rebel Propaganda! Please, don't listen to this.
The Rebel Player wants you to not bunch up. Then he can use the other surges (Stun / Pierce) and you can't use Cower or Protector or all these good Command Cards ...
Let me explain:
I set up some demo games for a friend. He is a really good tournament player in other games (e.g. Warmachine), a good strategist and a fast learner. Some days later, he wanted a competitive game. I gave him my 4x4 and used my Rebel Blast against it. I told him in detail what the figures do. I was pretty confident. I lost as hard as one can.
His strategy was to bunch up with my rebels, especially those, that already had activated. Each Royal Guard figure was always adjacent to at least one other Royal Guard figure. The Imperial Officers where to far away to hit them.
Most of the time, I couldn't use Blast, because my Rebels would have taken as much damage as his figures. More often than not, I didn't roll the double-blast, often not even a single blast. More often than not, I had to use Pierce to get Damage through and therefore couldn't use Blast. Protector and some Command Cards sometimes completely prevented damage on the target, so Blast Damage wasn't resolved.
It was a devastating game.
For the German National Championship I used the 4x4. When I played against Rebels, I used my friend's strategy. It works. My 4x4 didn't lose a game against Rebel Blast since then.
Some Math:
red die + yellow die = average 3 Damage
black die + Protector = average 2.5 Blocks
In many cases, the attack either deals no damage, or rolls one Surge but needs the pierce to deal damage. Often enough, you don't even roll a surge, or the black die shows a cancel when you do.
Edited by DerBaer
with 6+ models focused after turn 1, I'll look forward to go haywire on those poor Royal Guards 
