Jamie B. answered 02/02/20
Particularly Qualified and Highly Knowledgeable Here
Step 1: define more stable--stability is a relative term.
The chemical environment defines stability-- but that aside...
Back-bonding is interesting--and I reveal I'm out of the loop-easy research.
A look at the lone pair -> empty pi orbital overlap could shed light--
To begin--what is your evidence of these species relative stability?
Thx--from the future. 2020