Irish Marriage Records

[Maiden Stone]

I forgot to ask, why would the location be recorded next to the witnesses names and not those of the people being married?

It was just the way particular priests wrote entries. Compare with registers of same parish from 1870's when abode was written after names of people being baptised or married and before names of sponsors or witnesses.
There seems to have been no set way of filling in early R.C. registers. Last column in marriage registers at my grandad's parish, early-mid 19th century, had degrees of consanguinity/affinity of couple being married. Last column in registers at my grandma's parish had amount of stipend. Neither marriage register included residence.   
Some parishes had proper registers with headed columns but some used notebooks or what look like account books.