I always aim for limited movement in the hand
3212 1432 1432 1234 - doesnt seem to work well. After the last finger, 4, how do you get back to the repeat with the same fingers? 4 then back to 3 is bad. It also has a particular movement which needs to be controlled, that is the 1432 in the 3rd group of 4 notes, and it has an unusual effect on the flow of notes i think.
5432 1543 5432 1234 - also seems inferior because of the 5th fingers movement around the place which shifts the overall shape of the hand around (1 and 5 have the most effect on hand shape so they should be avoided to move around if possible if you are playing fast sections) , this is not easy to control for me.
Why do you aim for finger legato, i think it would be useless in this case. When you practice you should be playing in the p ranges so that you develop the touch, and aim to have a slight accent for the first note of every new group of 4 notes. the speed needs to cause crisp notes, not a legato effect. That can be dabbled with later on, but aiming for legato through the fingers is suicide.
The reason behind BAR7 3212 1432 BAR 8 3212 1212 , is to keep the pattern within the 123 fingers and limiting the others. Since 123 is the strongest fingers in the hand, this group of notes should be rather confident and easy to play.