For me, it works best to put more time between upper-body workouts (more recovery time), so I would do Meso 1 as you suggest.
I don't see any benefit from doing Meso 1 in the order suggested. In fact, I had asked Cathe about why she sequenced the Meso 1 workouts in this way, and she said more or less that it was for variety (a different type of stimulus to the muscle) This wasn't a convincing enough reason for me to want to try it that way, LOL! The STS manual also suggests that one can do the workouts exactly as you suggested.