I think it is interesting that neither Regina or Tiana are doing very many scene with Tremaine. It really does make it seem like she isn’t really the villain at all.
The reason the timeline is discussed is because, in my opinion, that is the easy part to get right. If the writers can’t get that right, such a simple thing to get right, then they can’t get emotional growth and consistency right and that is why their characterization is a mess and that is why the show is a mess.
This is just a symptom of the real problem with the show and that is bad characterization because of a completely lack of ability to even be the tiniest bit organized or consistent.