There's a fun thread in the fanfiction.net Hogan's Heroes forum called "Which of our heroes," it's kind of run it's course after quite a few years, but was quite popular as people asked and considered questions like "Which one is a dog/cat person," "which one is the best athlete," etc.
We see more of the orphans' personalities, obviously, in the movies, though on stage there's enough to get a little detail. Sure, there's not 168 episodes to help build the characters, but this might still work as a discussion starter to get more people involved.
On that forum, there are enough people one could answer and then ask another question. I don't know how many are on here, but we'll try. If nobody else replies after a whie, we can just answer our own and go home - but it's worth a try. :-)
Oh, with names, if you've read my fics (in my bio) you know my take on the '82 movie change is that Miss Hannigan called July that, she took the name Kate, and then another Kate came along so she went back to July; so July can, technically, also be Kate. So, when I say "July" I mean "the 13YO orphan who is a mother figure." If you're using a different formula, it might avoid confusion if you say "universal July" meaning she's something of a combination of the play/'99 movie and the '82 one.
I'll ask a fairly obvious one to show a few things (multiple possible answers, for instance) and one not so obvious that anyone can come up with something creative to answer. Then, the person who answers asks the next question that the next person answers and asks one...
The (kind of) easy: Which of the orphans is destined for show business?
My answer: Duffy, Annie, and Molly.
Annie has to be the best singer, but I think it takes one of the older girls to get the others really wanting to do it a lot. Someone had to teach them how to do SMILE and HKL while getting in rhythm, etc.; especially since SMILE is one they heard. I've heard my young (4-9) cousins at Thanksgiving asking Alexa to play various Disney/Pixar songs and singing and dancing along, There's a difference between girls who do it for fun and who are really dedicated. I don't know if all 7 would be really dedicated, though if you want to say they would be I wouldn't argue. However, one of the 3 oldest would have natural talent and be able to teach the others, at least up to her level. And, hearing the Boylan Sisters on the radio can help her know how to do it better.
Why Molly? She likes to take after Annie, she has a loud voice that she has time to train with once she gets out, and she likes the attention. She might be the kind who doesn't realize how tough it is, but she's determined enough I think she'd be in *something*, though TV could be more her style. Maybe as a female Wild West hero in the '60s in their universe, in a show called "Your Days Are Numbered." :-)
Now, the tough question - whichever one has an answer also should ask a question. (And if you want to answer it and you're 2nd, go ahead.)
Which of the orphans is most likely to leave the big city and settle down on a farm in the Midwest?
So, this may not have taken off, but that's okay. They are pretty young and it's harder to pinpoint the characters, as I said.
I will answer my question and give one more just in case others thought this was a bit too contingent on who adopts them, etc., too (admittedly it could be any in the right circumstances):
My answer to which one chooses to move to a farm as an adult would be Tessie. I'm thinking that with how much she worries, she might find working with animals to be lots of fun, and while farm life is hard work, animals can be very comforting, meaning it's a lot better work than all that cleaning and sewing.
One that's not so contingent on who adopts them (or who they marry, for that matter):
Which of the orphans learns to fly a plane?
If nobody answers and comes up with another here, I'll just come up with my own and drop it.