"...the Christian supercession of the second quotation
in the book of Matthew...." ??? I'm not sure of the point. Do you mean there is some 'official' version of which biblical passages are 'ok'?(whatever THAT might mean in 100 conflicting Christian doctrines)

Whatever supercession you might cite, my point remains....Christians can & do find biblical support for almost any point of theology under debate. The bible is full of 'slewings', from Sampson to the stoning of harlots.....and the libraries are full of analyses debating whether they 'really' meant it was ok or not.

You really want to comprehend the arguments about 'rights' and 'fairness' and 'value'? Read Kant's Fundamental Principles of the Metaphysics of Morals and 20-30 other philosophical works. If you are an honest man, you will emerge more confused than ever....and very likely become a pragmatist. Which will get you many disputes with other pragmatists over which opinion is the more pragmatic.

Bottom line: it is not a simple issue, and our challenge is to try to create a world in which death sentences are not needed...and in the meantime to cope & adjust.