keep in mind that the jews also have a different numbering of the 10 commandments, that differ both from the “catholic” and “protestant” sets. part of the reason for the change from jewish to catholic numbering is a shift in understanding in human dignity. under mosaic law/eastern culture, the wife was part of the husband’s “property”. under the law of Christ, we all have dignity as individual persons - and this is reflected in the catholic church’s 10 commandments. our 9th and 10th commandments are don’t covet your neighbor’s wife and don’t covet your neighbor’s property. protestant and jewish numbering still include the wife as part of the husband’s property.
you may also notice that the protestant 2nd commandment is not directly found in ours (or the jewish) - i.e., no graven images. in jewish and catholic understanding, this is logically part of the commandment to have no other gods before Me.
personally, i think part of the re-numbering by reformers was in an effort to directly attack the catholic church with idolatry charges via their new 2nd commandment - which, as anyone who looks into catholic practices can see, these charges are completely lame. beyond that, i can see no reason for changing the 10 commandments…only a knee-jerk reaction to anything “roman”.
hope this helps…
RyanL