I have not used either extensively or in a custom, but I do see the archetypal difference between the two programs. 
RM is about beauty, emotions, expression, and dreams. It’s a Way of Being – almost a type of Spiritual title. 
Comparing to UA, Renaissance Man does NOT identify himself as an Artist or a Craftsman. Neither is he interested in “increasing output” (creating more & more works), nor in making money from his creative expression.
Personally, I have always held UA to be a Mogul for Artists.
Just like GMX, MTX, BMX include money-making (career building) along with the Mastery.
If I may liken these two to another twosome … Wanted and Sex-&-Seduction.
Wanted & RenMan are deep internal titles, that end up showing effects outside.
UA & SS are WeaponX titles, that work purely by learning through actions.
They don’t NEED each other, but they WILL enhance each other.
