It's personal IF you are the only person working on the profile. Otherwise, it's a matter of consensus among those who are actively contributing/monitoring the profile (NOT just the PM -- the role of the PM is to coordinate the profile, they don't control it). Except in the case of very short and simple bios, subheadings are generally desirable, just as you would expect in a wikipedia article. I'm not sure well-chosen subheadings need to detract from narrative flow. However, in the case of profiles where some of the important genealogical facts are unsettled (eg, a lot of older profiles), it is often necessary and desirable to sacrifice some narrative flow in order to have a full discussion of the evidence.