We look at the humble devotee, what they can do mechanically and more importantly: what is in there for the narrative.
I recently had a discussion with my Brother in arms, Barrackus. He had some fine character ideas around the Devotee talent (core, pg. 133) that I like to share.
So we will first dip into the mechanics of the talent and then explore some character ideas around this talent. Some of those ideas focus on the narrative opportunity and thus might not be for the min-maxers among the readers.
The Crunch
In short, the talent provides you with a number of henchmen that are either (a) a selection from a specific Troop entry from the Bestiary or (b) custom made with attributes and skills that are equal to yours and caps at 1+Double Rank (3/5/7). We will focus on option (b). This will give them final skill pools of approximately (6/10/14), if you can boost your stats accordingly.
This leaves us with clones of the PC (player character) that will do what you ask, attack your enemies and may jump into any form of attack and die for you (the respective initiative assumed).
Regarding the number, you get 2+Double Rank (4/6/8). So quite a bunch of dudes and gals.
Do what you ask
As they have an identical skill set, the more or less can work as your proxy for specific tasks. You might need the skills yourself but if you have them you can probably send them to e.g. scouting tasks without facing the immediate danger. I think it is solid at Rank 1 (pool of 6 dice) but really comes to live at rank 2+. 10 Dice is nothing to feel sorry about. Let's think of some usages:
Scout (Stealth and awareness) an area.
Repair (Tech) some dangerous equipment.
Defuse (Tech) a bomb.
Ask and interrogate (Insight, Persuade or Investigation) guests at a party.
Lead multiple troops into battle (Leadership).
Climb (Athletics) dangerous places.
Overall, with skill clones, this is more a flavor bonus (more on that later). Most of those could be done by yourself. But it might be cool to send your followers, or safer not to attend yourself. Or you need to be on multiple places at once.
Fight at your side
So they are a Mob of Troops. This depending on their equipment might not be to effective. But, maybe they have all plasma guns, then it might be quite deadly. As this highly depends on your table, let's assume they have only mediocre equipment. This still leaves them with a potential skill set to execute Interaction attacks. Mostly Tech and Intimidation attacks might come in handy. But others might work to. More or less allowing you to make an additional attack (with the mob) without making a multi-action.
Take one for the team
So the last ability allows your devotee to make a reflexive imitative test against DN 5 to take the hit (and die) for you. While this is strong. Passing a raw Imitative test vs DN 5 is not easy and will probably only work reliably with Rank 2+ (5 or 7 dice). But might be a shot with a specific build (more on that later too).
Character ideas
So with this in mind, lets see some broad character concepts we came up with. First some sort of Bounty Hunter with supportive droids, servitors, servo-skulls and other machines. The other one is a deadly mask wearing cult assassin with a bunch of Doppelgangers.
Bounty Hunter
So the concept would be a skillful character with a bunch of supportive characters that will be used as skill proxies. Each could be very distinct and represent one or two skills. Need to treat a wound (maybe in battle)? The Medicae Servo-skull has your back. Your Cyber-Mastiff grapples the enemies? Athletics Interaction attack! Repair Servitor. Scholar Scribe. Overall endless opportunity...
You could use Advanced Char creation as this will free some points from the archetype ability that could go into more attributes and skills.
Mirror Assassin
Ok this is fancy. Idea is. You have your PC and a bunch of identical appearing Doppelgangers. You look alike due to surgery, a mask or other reasons. The other chars never know exactly with which of you they are talking. They can work as a skill proxy, sharing your capabilities. Should on die, never know if it was you, another faceless assassin will take its place. If you take the Death Cult Assassin, your focus on Imitative will allow you to more reliably use the sacrifice ability of the devotees. This would allow you to dump Toughness even more as you can use Agility for your Determination rolls and an occasional sacrifice.
The Mob will also come in handy with Athletic Interaction attacks while the real assassin (you) deal the killing blow against the vulnerable target.
Conclusion
So here we are. Maybe the 30xp price tag is to much for maybe mostly flavor. But I think you can have some very cool concepts. And if the table/GM is a little flexible, you will have very cool narrations to tell. Also, I think they can also be quite a support in combat depending on the circumstances.