Rivers has 47 turnovers in the last 2 years.
Mark has 52 turnovers during the same amount of time.
Both have been pretty bad at turning the ball over the last 2 years. The difference is in the amount of TDs each QB throws. Rivers threw 53 TDs in those 2 years which gives him 6 more TDs than Ints. Sanchez has thrown for 39 TDs the last 2 years which gives him 13 less TDs than he has thrown Ints.
Rivers has also had plenty of seasons with much better numbers. His best TD to Int ratio is a plus 23. Mark's best TD to Int ratio is a plus 8.
There is no maybe about it for me. I'd take Rivers over Sanchez any day.