Is a SR2+ substituent really more electron-withdrawing than NH3+?

As the electronegativity of nitrogen and sulfur are around 3.04 and 2.58, respectively (according to the Pauling scale). So according to that, $\ce{NH3+}$ should pull the electrons more towards it than what $\ce{SR2+}$ should. This argument has been put forth by Jan in his answer to a similar question here.

However, my textbook (Organic Chemistry by Subrata Sengupta) states that the exact opposite is true. Who is correct here?

• I'm sorry, I'm unable to find sufficient data so as to draw meaningful conclusions at the moment. I'm therefore deleting my answer, if I happen to stumble upon resources that may interest you, I'll add them at a later time lest someone else hasn't provided an answer by then. – Berry Holmes May 18 '17 at 13:58
• Mods decided this wasn't a dupe of the linked question. If anybody would like to discuss it, please make a post on Chemistry Meta. // I have reopened this post, which was your original question - in the future please don't repost, instead edit your question, or if you wish, post on meta. Thanks for understanding. – orthocresol May 19 '17 at 22:51
• Thanks for your concern @orthocresol. I will keep these thing in my mind from next time. – chail10 May 20 '17 at 12:25