So what are the differences between the two sentences besides that? I mean do they mean exactly the same thing and are could they be used in the same kind of context?
When you have a compound verb - several verb forms in a row, the adverbs usually go most naturally after the first verb in the sequence, thus: Kim wouldprobably justhavesaid that she won't back you up.
This pattern is not fixed in concrete, so you can move the adverbs to the right (as long as you don't place them after all of the verb