To me the logical division of stamps on a site with users from many countries, would be by continent further sub divided by country, but that may well not be the way a stamp expert sees it.
That is why I suggested a revamp of all of the categories, with input from the sellers, so each is shaped to fit those who use them, & understand the needs of both the buyers & sellers for that type of item.
There was a major revamp of the Sports Cards section, I think baseball was the first one completed, it was then suggested that the same sub categories be applied accross board.
This seemed to stall, when they expected Gazza to add a category for rookie to football(what you call soccer) when queried the reply was well as football (soccer) is so popular it should be included.
The poster didn't understand that although copying the baseball categories might work for other American Sports, they made absolutely no sense at all for football (soccer), as known by much of the rest of the world, any changes to those categories needed input from those who understood what is needed.