when this card is played, in what order is damaged assigned/units are routed?

I'm little tripped up on this due to playing it with Zarathur. Since he's at the planet where I play it (let's say for this example), does all the dmg assigned to enemy units get increased even if I choose to rout him?

Also, It might be advantageous for one player to decide not to rout a few guys if the other is going to rout all, etc...

Just some clarification needed please and thank you.

Here's a link to the same question: http://www.cardgamedb.com/forums/index.php?/topic/19096-card-nurgling-bomb-in-what-order-are-units-damagedrouted/

The cardgamedb thread gives the full detail. Here's the shorthand for those that don't want to read through the whole thing:

1. Person who plays Nurgling Bomb decides what to do with all of his units (damage or rout). Then the other player makes his choices.

2. All damage and rout, for all units, then initiate and resolve at the same time.

3. #2 means that the routed units arrive in their new location (HQ) at the same time the damage counters are physically placed on the damaged units.

4. #3 means that a routed Zarathur will still be at the planet (and able to use his interrupt) when damage is assigned to the damaged units.

One other important note: You do get the opportunity to shield the damage inflicted by Nurgling Bomb, per unit.