Major apologies for not getting online recently, things have been busy.
The regular snare hits were placed on the treble clef A position because that is where I traditionally have written them. They may be changed to any location of your choosing by editing the percussion layout maps. These may be found by opening the Score Manager window > selecting the snare staff in the upper half of the window > then in the lower half/right side you should see Notation Style: Percussion and a Settings button. Click the Settings button and in the window that opens it is here that you can Select, Create, and Edit these layouts. Highlight the map you wish to Edit and click the Edit button. In the dialog box that opens, navigate to the sound you want to edit (left side) and on the right you are able to edit noteheads and staff positions. Tutorials and the Finale Knowledge Base/Help Guides can provide additional information.
Hope this helps and let me know if you need anything else.