I was just thinking of how to get the tags you want and not have the "cut off" numbers. It's a multi step process but should prove helpful.
Write a quick "dummy" post then hit publish so it brings that "add a tag" box up.
Then start typing in the tags you want for your other stories. Write down the ones you want that are relevant and have the numbers you're looking for. Then go back to each story you have and replace them from the drop down menu.
Hope this was helpful