As far as using Stormtroopers as minions goes, this actually goes a long way towards solving an issue that's plagued many of the prior Star Wars RPGs.
Simply, how can the GM keep stormtroopers from being a viable threat against the PCs from the start of the campaign to it's finish?
The d20 versions ran into this problem, particularly Saga Edition, where a group of stormtroopers (even using the Squad rules introduced in the Clone Wars Campaign Guide) were soon reduced to target practice by the time the PCs hit 5th level, as most stormtroopers could barely hit them, and when they did, the PCs often had enough hit points that your average blaster rifle shot wasn't that big a deal.
D6 faired a bit better, though stormies apparently had some hidden rules that were so well hidden that most GMs (myself included) never used them, reducing the Empire's elite soldiers into being little more than Keystone Cops clad in white armor.
Here, in EotE, a single stormtrooper isn't much of a threat, but when they start showing up in groups, that's when the PCs should get worried.
On your specific question, if splitting the stormies up as Sturn suggested, I think it'd be something like this:
Stormtrooper Group shooting at Stan: There's only 2, so they'd only get one rank in Ranged (Heavy), for a base pool of 1 Yellow, and 2 Green (Agility 3, one die upgraded per the minion rules for there being 2 minions in the group).
Stormtrooper Group shooting at Bob: They'd get 2 Yellow and 1 Green (Agility 3, two dice upgraded per the minion rules for there being 3 minions the group)
A lone stormtrooper would just be rulling his 3 Greens due to his Agility of 3, since he's operating alone.
That help any?