You have a ton of RB depth so I can see why you;d be interested in making a move like this, but:
1. How many RBs can you start - mandatory plus flex?
2. How many will you start in a typical week (or, really are you more likely to start say Carson or Hunt at flex over one of your WR options)?
3. Do you think Newton will continue to perform at this high of a level, and do you think Wentz will continue to perform poorly when his WRs are back?
4. Based on your scoring system, does your weekly lineup improve by slotting Newton in at QB over Wentz but dropping from Carson/Hunt to someone else at flex?
Depending on the answers to the above, I can see making a deal, but giving up one of the few healthy every down backs (even if it is your #3 RB in Carson) for a QB upgrade is a little steep, but if it improves your lineup enough it may make sense for you given your RB depth.