I agree with you that the wiki doesn’t specify any strict rule about changeset size. In my view, the main issue with your changeset wasn’t the number of edits, but that it included modifications in two different cities (and provinces).

I’m not sure who complained about too many small changesets, but personally I think it’s better to keep one changeset per city, even if it contains a lot of edits. In your case, the cities aren’t very large, so a changeset like yours wouldn’t be too big or too small, it seems perfectly acceptable, even if it modifies all the websites at once. For larger cities, I might split it into smaller changesets, though.