I think it's possible. Though personally I wonder if what SIU means by "heroine" is the same thing we're thinking of. And if it is then I'd wonder if he'll stick to that plan.
Because, here's the problem with either Enne or Adori as a primary love interest, the later that's established the less effectively he's going to be able to form a deep romantic subplot. Not saying it can't be done, just that's it's really difficult to do well. Just think about it. He needs to create a foundations and build that up. Unless we get to Enne or Adori pretty soon here starting that up is going to be awkward. Which with Adori he could play off for laughs pretty well like he's done with Yuri. With Enne I think it might be harder because she's so inherently tragic.
I honestly think there are two effective ways to do it.
The first is to have Androssi and Baam become an actual item here pretty soon. Build that relationship up a lot. Then (and it kills me to say this) have her die tragically in whatever will happen with Anak. Then SIU could have a character like Yuri, Enne, or Adori step into that void. I don't like this for obvious reasons.
The second much more preferable option is to have Androssi compete with somebody for Baam's affections. Somebody like Yuri or Yihwa. Then build up both sides of that at the same time and as long as Baam doesn't reject either he'll default to the harem route. On that route. It's easy to add in late love interests because your building into a relationship that already exists.
Anyway... I still think Androssi is best girl.