in 2017, the packers only had rogers and hundly on their roster, when A-Rod went down the team had to resign Callahan whom was one of the final roster cuts. I believe there was some issues in 2013 when Tolzien, Rodgers and Wallace all went down, but I give you that was a freak year. The issue with keep 2, is that if you starter goes down, you are rushing around during the week to get a backup, unless you have a practice squad one you are comfortable with promoting to the main roster. I'll give you, that if A-Rod goes down, it doesn't matter if you start Kizer or Boyle, its going to be hard to win many games with either, so you might as well put as much talent on the roster as you can.