NCR has a long relationship with RNS - they use their articles more often than not. The fact is that both sites are rather liberal and left-leaning.....and are closely related.

The relationship is very close and well documented - note articles such as "NCR contributor named CEO/Publisher of Religion News Service" (article on NCR from 11/2016).....

Back in 2011, we learned that an editor for NCR was a news editor for RNS (https://www.ncronline.org/books/2012/09/amid-tensions-church-survives)

Etcetera.  The relationship is very tight.  So your comment that one source's position is not necessarily the position of the other is rather slim....