The only thing that really stands out about the companions we have so far is that they have some of the most outrageous backstories I've seen in a while (and I've seen some questionable backstories)
I've been gaming a long time. I have no problem with outrageous backstories, except when they're used to justify characters that are beyond perfect at everything. I once found a character sheet someone had left behind at a con from a superhero campaign. It was for a Spider-man clone who had PHDs in 8 different hard core sciences and spoke 8 languages fluently, (without an accent) and only too damage from super glue. But hey, the player justified all of that with their ridiculously over-the-top backstory!
That said, if a crazy backstory is fun, or funny, or just works, it's all good.
