wow, punting a game because people are terrified of Gerrit Cole! 
There may be a statistical argument around pitching Sanchez against Cole and going with the big three afterwards, but that is why decisions are not made by computers alone.
You never know when Cole will have an off night. More importantly, baseball is a game of habit. If Dave Martinez walked in the clubhouse over the break and said, "We are going with Sanchez in Game 1" it would have caused confusion and taken the team out of their zone. Let the Astros be afraid of playoff Strasburg, I want our Big 3 going Games 1, 2, and 3.