I have argued that with vector utility/value there is no such thing as "the best college." (See chapter 2 of my book Twelve Papers, at www.robert-w-jones.com under "book".) Similarly, it may be that there is no such thing as "the best of all possible worlds."
But world A might be "better than" world B. Suppose the vector value of worlds had only 2 incommensurable components (x,y) and that there were 3 possible worlds with: W1=(1,2), W2=(2,1), and W3=(3,1). Then W3 is better than W2. They are equally good according to component y and W3 is better than W2 according to component x. But we can not judge which of the 3 worlds is the best of all. W2 and W3 are better than W1 according to component x but W1 is better than W2 and W3 according to component y. If some one world had the highest value for ALL of the components (x,y,z,....) only then does a "best of all possible worlds" exist.