I just had a thought. I think the OP's idea was too much, I didn't really like it. But I can see why others do.
Rather than have "Archetypes" as such, what if certain backgrounds simply put your skill points somewhere
So you start with XX number of skill points. You can essentially just sit there and pump away and stick them all into a variety of different skills.
Or you can select some "backgrounds" which predetermine some of the skill point allocation.
So if I want a medic, I can just pump points into the "Medic" skill, and thus have that affect various things in game.
OR
I select medic in my background. This gives me a little blurb of some form about medical training, (perhaps even allowing several differing options. Ranger Training, Parents were Doctors, Fascinated by flesh wounds etc) but in addition it automatically pumps X number of points into the medic skill. You can still modify it, by adding or removing some points from it, if you don't feel it was the right amount, altho I would expect there to be a minimum point use.
Benefits - You get a bit of background, this could be used to expand on stories, so in the situation where you need a medic, the one with Medic skill might actually get some minor conversation changes (not game changing) that are based on the history. "Oh yeah my Mum told me about what that rash means, you've been places you shouldn't" as compared to "You know what that Rash means, you've been places you shouldn't" (I would expect better writing

)
- The points get allocated automatically, so then rather than clicking on something or sliding a bar or whatever until you are at the exact point you want, you get what the devs think is a reasonable amount of skill.
- Its not be all and end all, you can then make modifications up and down to show better or worse level of skill (a smart dev could even factor that in. IF below X then points then player was lazy in class).
- Its optional, you could just pump the points into Medic, and not worry about the background.
Another example
Boxing
Background - The player was teased a lot as a child, so her Dad taught her to box. The player tended to get into fights, one day Bob the Boxer, prevented her from getting beaten by a group of other kids, so he gave her some training. Etc
Skill - Pumps X points into Hand to Hand(boxing).
So essentially the "backgrounds" would simply be a way of creating a bit of background histroy and allocating the skill points that you could have allocated manually anyway.
I would also suggest that the backgrounds be a bit changeable. Perhaps if a hometown(other than Ranger HQ) is mentioned, it gives you a choice of several. Other things, like names and that sort of thing could be somewhat customisable, using variables in the game to provide context.
You could even put bad stuff in there.
So in the boxing example, you could have a Background of "Child was prostituted out by their (Choice of Parent,Adopted Parent, Kidnapper). They fled one day offering themselves as payment for training in boxing, the trainer (accepted and, refused but) trained the player. Once the player was old and good enough they hunted the (original abuser) down and proceeded to (beat them to death, Beat them nearly to death, find them dead already, forgive them, spit on them and walk away).
This could then allow you to build conversations in the internal party or with NPC's using some of the above information as keys to conversations.
You could also then combine it with other backgrounds.
It might require the backgrounds to have an order of precedence perhaps. So maybe your character thinks that the bad boxing example is pretty much the defining moment of their life. Or maybe they just want to forget it and get on with their lives. So you give the background a simple "importance" factor. 1 for lifechanging, 5 for it happened, I am done with that. This could then be used to further modify the conversation.
I think something like that would work really well.
The only problems I see with it, you would need a lot of playtesting to make sure it works smoothly, and it may well be quite intensive writing like that.
The beauty of it of course, is that it is optional. If you want to just pump points into your skills and be done, then thats all you gotta do.
I rambled a bit here, so I apologise if it is confusing. What do you think?