I think there are too many (no-name) angels at the moment for any of them to be 'leading'.
If you ask Regular Joe who are VS angels at the moment he/she would probably say Gigi/Bella/Kendall or stay mum.
While couple of years ago our Regular Joe would mention Adriana, Alessandra, or even Miranda. Not to mention Gisele, Tyra and Heidi.
I believe Lily is already out. I don't consider Candice and Behati angels anymore as well since they're not doing anything except walking the show.
As for the others - Taylor has a lot of followers but seems uninterested.
Barbara could be the new 'big name' - but the problem is that she will hardy get enough attention with so many angels around.
Sara also doesn't seem much connected to the brand.
I've thought the same about Stella, but they seem to be using her much more recently.
Grace is pretty and well-spoken but I'm not sure that she has the 'star power'.
Elsa is regular - but she's just there doing the minimum needed.
Similar with Jasmine (whom I really like for the brand).
I would definitely keep Martha - maybe not the sexiest (prettiest?) one, but definitely well-spoken (great for TV shows, events and similar).
Lais seems to be off (maybe that's just my impression).
I really though that they are going to make Romee their 'main angel' during the last year but now she seems not to be around anymore.
Josephine has also faded within VS. I'm not sure who's to blame for this - VS, her agents or herself as she had everything going on for her when she first became an angel.
Altough I kinda like Leomie, I don't think her and Alexina should've gotten the angel contract. They somehow cheapen the brand IMO (if that's possible).
I'm not sure if I forgot someone.
I'm expecting Sara, Lais and Martha to leave first (besides Behati and Candice).