If a Unit of Speeder bikes both fire with the bikes blaster cannon instead of the hold out blaster they each contribute the red black and white dice. since the Impact keyword is on the weapon they stack because both bikes are contributing to the attack pool. the attack would consist of 2 red 2 black and 2 white dice and have impact 2.

is that statement correct?

I am using pg 30 for my conclusion

"If a unit performs an attack using multiple weapons that have the impact x keyword and those weapons contribute dice to the same attack pool, the x values of each impact x keyword are cumulative. For example, a unit that performs an attack using both a weapon that has impact 1 and a weapon that has impact 2 contribute dice to the attack pool, that attack is treated as using a weapon that has impact 3 which allows that unit to change up to three hit (?) results to critical (?) results."

Yes that is correct.

Each model has a separate weapon. Weapon type and number of weapons are two separate things.

100% correct, can confirm. Just played a game with this rule.

If your unit takes 3 damage (and subsequently you lose a bike) you are reduced to 1 red, 1 black, 1 white, and Impact 1.

thank you very much

So if I have 5 stormtroopers throwing 5 impact grenades, I have impact 5?

2 minutes ago, That Blasted Samophlange said:

So if I have 5 stormtroopers throwing 5 impact grenades, I have impact 5?

Correct

Yes indeed. Witnessed that tonight!