I somehow see Kentucky as a much weaker challenge to Duke than MSU. Remember, Kentucky lost to Duke by freaking 34 points! This same Kentucky you place ahead of Tennessee lost to them twice (although they beat them once). Tennessee in its turn lost to Auburn twice and to LSU. Oh well, it is true that MSU lost to Indiana and Illinois, but they have Nick Ward back, now, and are being called a potential Final 4 team. They have a great coach, great defense, they are great at rebounding, and Winston is great at closing plays. They also have a lot of experience. Remember, they went to the championship game last year. Not to forget, they have depth, with a great bench.
Duke on the other hand only lost two games without Zion, one of them, while missing two other essential players. The one game they played complete and lost was to Gonzaga. I watched that game. Duke had like 3 opportunities to win that game in the last minute and the ball would just circle the rim and drop out. Duke should have won that game. But it happens. They lost to another #1 seed.
So, the overall #1 seed should have had the weakest #2. Do you really think that MSU is the weakest #2? From Duke's standpoint, better the devil known (KU; they beat them 118-84) than the devil unknown.