I think a separate motto for Knights and Lords of Stonewall is a great idea. As has already been said, Star Wars and Star Trek have very different ideas and cultures. Strength in Diversity resonates well with Star Trek, but not so much with Star Wars. I'd think that the Jedi surprising the Sith and the Sith suppressing the Jedi for thousands of years at a time would hardly be considered a diversity friendly environment.
I'm more curious about how we can tie the Motto into our 'blurb' and why would a group of Jedi and Sith decide to unite?