You don't know what injuries the 2020 season will bring, so for an honest comparison, you can't count the injuries from the other seasons you are comparing it to.

A healthy 2014 and 2015 Taysom is an obvious upgrade. 

While 2013 Taysom struggled initially in the passing game (no thanks to the large amounts of dropped balls by his receivers), he completed over 62% of his passes in the final 10 games of the season. Also, if we are being honest, the 2020 WR outlook is pretty bleak.  Having a dominate runner at QB would mitigate such a weakness.

In 2012, Riley Nelson was very good before his injury, plus you have Taysom Hill as backup. 

For 2011 it is a case of known vs unknown.  In 2011 Rliey Nelson gave us good QB play.  2020 certainly has higher potential, but then again so did Jake Heaps.  So did the 2019 QBs, and I'd take 2011 Nelson over 2019 Wilson.  However, 2020 Wilson will (hopefully) have had a full offseason under his belt, so a 2020 Wilson will most likely be noticeably better than 2019 Wilson.  It really depends on how ones preference.  The proven good vs the possible great (or mediocre).  Either way works.