An interesting take on the motto here:
https://jeffbeaty.com/2016/03/non-vi-sed-arte/
Please excuse the following ramblings, given various uses of the motto, but the following struck me as potentially interesting
I have not fully researched the use of the motto back to todays 'Special Boat Service'
https://en.wikipedia.org/wiki/Special_Boat_Service but have heard accounts of it being associated with Roger Courtney of Commando Special Boat Section - I think this may arise through confusion of the abbreviation SBS. Roger's brother Geoffrey suggests adoption of 'Excreta Tauri Astutos Frustrantur' ('Bullshit Baffles Brains') for Commando SBS. I have an idea that 'Not by Strength by Guile' was adopted by Jellicoe's Special Boat Squadron - If so, this is an interesting link between the Beatty and Jellicoe families (recalling respective exploits at Jutland) ie Jellicoe's son's use of the Beatty family motto.
Any thoughts appreciated - PM please if a diversion from the main subject of this thread
Mike