I;m definately taking Rivers over Romo.I would strongly disagree that Rivers is some big advantage over Romo. Personally, I think Gates>Witten is a bigger margin than Rivers>Romo.
I feel like you are following less important stats here. Gates led the league in yards more than Witten, TD's more than Witten. Gates was arguably the best TE in the NFL for a stretch, that was never the case for Witten.
Using 03-17 as their comparable career template, year by year:
Gates wins: 2003, 2004, 2005, 2006, 2009, 2010*, 2011, 2014, 2015
Witten wins: 2007, 2008, 2012, 2013, 2016, 2017
*Gates was on pace for the best season in TE history when he got hurt, so even though Witten had more yards, Gates gets that year for me.
That is a 9-6 head to head win for Gates. His peaks were also much higher in both yards and TD's by a very wide margin.
Witten missed one game in his entire career, Gates injured a lot.
Witten had 4 90 or better catch seasons, Gates never had a 90 catch season.
Witten had more 900 plus yards seasons.
More pro bowls as mentioned.
My song n' dance is this is close, and a real legit case can be made that Witten had the better career.