Beni,
“Nowadays our penuyos are all niddos and therefore the issur yichud is d’oraysa, just like an eshes ish.”
My point was it is certainly LESS than Eshes Ish – See Tosfot סנהדרין לז א
“התורה העידה עלינו סוגה בשושנים”
Tosfos clearly sates that it is less….