I guess what you say about endings is intended for Menke. I never mentioned any -een ending.
Sure, I won't say it's the only possible origin. But there definitely exists a Sanskrit name 'suvijna' with the meaning I gave, and the change to Suvin is easily explained.
As I indicated, it at the same time explains the name 'Suvigya', which is not proper Sanskrit at all:
"XX is generally pronounced as XXX (gya) or XXXX (gya). The correct Sanskrit pronunciation, however, is XXXXX (jna)."
(Taken from http://rajbhasha.com/learnhindi/Chapter05.htm