The history of hymn tunes is all about evolving musical styles and adapting old material.
The Wikipedia page gives a summary for this particular tune.
It's original form was...
The German Wikipedia page shows that mensural notation in modern notation and then in metered form...
The point is that we can't even begin talking about different forms of the tune without first acknowledging that there are several historic phases adapting the tune to changing notation and rhythm systems. This addresses directly the first difference in the two examples you give where the barline is placed at different points. It also sets up the general idea that these tunes are adaptable.
Now let's move on to the harmonization.
Your harmonizations of the two examples are:
C: I | V6 iii vi V/V | V
C: I | I V6 V vi | V/V V
It should be clear that the general harmony of those two is basically the same. I tried to line up the similar chords visually. Both phrases use six chord. The only difference is the first one uses a
iii mid-phrase and the second uses
V to harmonize the
B natural of the tune.
Bach wrote three harmonization that appear in the 371 Harmonized Chorales:
One of the examples has the melody beginning on beat 3 and a long note on "borg" with a long pause. The other example has a shorter pause and the melody beginning on beat 4. Why is this happening?
The second example follows the notation of the Bach examples using only a quarter note with fermata (or comma) to indicate a pause.
The first places the barline differently, but strong beat positions are still the same. The first note is on a weak beat.
Both move by quarter notes until the phrase end. The ending is supposed to be long, but it's open to interpretation how long to hold the end, because they all have fermatas/comma.
The wiki page shows two other rhythmic forms, rhythmic and isometric (I confess I don't know what those terms mean)...
Ultimately, I think the answer is the rhythm of the original mensural tune is open to interpretation when you put it in metered form, but overall the general rhythm is the same: start with a weak pulse, three strong pulses, end on a long, strong pulse.