Tough one, as I quite like both middle names. In saying them out loud, I find that
Sebastian Lucas flows off of my tongue very naturally and easily, while
Sebastian Joseph is a bit "sticky" going from the "n" to the "J", though it's not actually difficult to say. With
Sebastian Lucas, I enjoy the variety of sounds between the two names. With
Sebastian Joseph, I find the "tian" sound of the first name very similar in sound to the "J" sound of the second, so it's almost as if a repeated sound is quite close together, but it's not a big deal if you love the names.
I get a bit different feel from the names.
Sebastian Lucas strikes me as fun, energetic, precocious.
Sebastian Joseph feels to me more serious, reserved, studious. I see both as handsome and friendly, approachable.
Have I helped at all or made things worse?