Sorry, I am mistaken, the Unit is being shown, so then you should be able to have multiple stickers. Previously, you could include all of them in the 'units' parameter and only one in the 'unit' parameter, which was shown, but now the 'unit' parameter is the only one being shown, which is connected to the Category. If the other units aren't included in the current Category, it just may make more work for that wikitree group.