Reason for female citizens was that there is separate template for women trained from house so double selection would not work.
Changed behavior is for selecting multiple women across civilizations what cannot happen because female capturing is not possible. In case it would be possible, triple click would work unchanged. Double click would select all women with patch instead all women per civilization, what seems more reasonable that one wants to select all women with double clicking.
Same logic applies to healers.
To the merchant and fishing ships. As they are not combat ships, it make sense to have separate selection groups for them with possibly more tiers for that kind of ships or captured ones if implemented. As other ships do not contain selection group nor their parent templates, double click uses template name for selection anyway so no change in this case.