Add-ons downloaded from Steam workshop are saved in several folders (which was critizised in other threads, but is **not** the topic of here).
In "...\Steam\steamapps\workshop\content\107410" folder you correctly have one folder for each add-on.
In contrast, in "...\Steam\steamapps\common\Arma 3\!Workshop" folder you may have several copies of the same add-on with different versions.
This is observed for any add-on that changes its name on an update. This is typically the case when the author uses versioning in their add-on title.
I request that the old add-on folder gets deleted automatically in "!Workshop" if the add-on was renamed by the author, in order to prevent such accumulations.