If you want to play Separatist Alliance, Twice the Pride is the Squad Pack for you… though not as surefire a recommendation as Hello There is for those dirty Galactic Republic loyalists.
The Separatist Alliance is best at action efficiency. Count Dooku, Separatist Leader is an excellent example of this. He’s an excellent duelist and has a frighteningly-effective ranged attack, but two of his abilities make Separatist Alliance Secondary/Supporting Units act on his turn. In typical Dooku fashion, the Count can stack failures on enemies’ attack rolls, and even flip an enemy’s Criticals into failures while he’s in Form II Makashi. If he’s too close to an enemy that whiffed a melee attack, he can swoop in and hit the offender himself.
Jango Fett, Bounty Hunter, however, is a weird addition. He’s a Separatist Alliance Unit, so he can benefit from Separatist Alliance abilities… but he is more of an irritation machine for your opponent than a true Secondary. Want to ripcord a guy off the point and/or building? Jango’s your guy. Did an enemy make the mistake of starting its activation within Range 3 of him? Get blasted, stupid. In a vacuum, Jango Fett is a goofy, trigger-happy character that your enemies will want to wound immediately… but he doesn’t elevate your lists in the way another Super Tactical Droid would.
Crucially, the Magnaguards are the best thing about this box. They are super cheap, excellent for escorting Primaries/Secondaries, and very tanky. Separatist Alliance lists will have a hard time not including these Magnaguards, so this box is an excellent buy.