It has been pointed out in recent debate that the "multiple complete season/series" sets "CAN" be set as box sets with children, but need not necessarily be so. Likewise a single-season TV set CAN have children, but again need not necessarily be so. The multiple season part of the rules is longer established, so it could be argued to have priority. However, in instances such as this it is going to be the individual sets' child profiles that have the earlier release date on it, so that goes in its favour, as well as the fact that more people are more likely to own this edition than a complete set. Trouble is, you can't just say to have individual child profiles without removing the "complete multiple series" box set rule completely and shifting entirely to child profiles (which I personally would like but of course would find wide opposition to). So, muddy muddy muddy!

I'd recommend a poll on this, since I can see this being an issue I will have to deal with myself as well in the near-future and I'd like to see firm opinions.

Your running into the same issue as we have with several Complete Series Sets.  Where the first disc ID was used to create the season.  But, when Ken allowed child profiles for TV seasons most of these got overwritten with just the data that is on these discs.

Did the season release come out before the seasons 1-3 set come out?  And is the season 1 disc 1 ID the same as the one packaged in the seasons 1-3 set?  If your answer is yes to both then I would say it is safe to overwrite the season 1 disc ID data with what is just in the child.

The main thing is someone will need to contribute the additional disc IDs that are included with the season 1-3 set to the box set contents of that DVD profile.