I don't think it's that sinister. Trubisky first was the smarter move, assuming it was as close as it was said to be in camp. Foles backing up is a known commodity, they knew he could come in when needed and run an offense. If Foles was the starter from day 1, that makes the season Foles or bust because if a move has to be made mid game or between games because Foles is sucking you've already told Mitch he's not the guy and we have no idea how he would respond coming in mid game or between games. Mitch was done as a Bear if Foles was named the starter for Week 1 or he lost the job sometime in the season, they gave him the one last shot it didn't work out.