Not sure why you're arguing this. Estrada being better than Doubront doesn't mean you extend him which is the topic at hand. Let's just all be happy he's been doing well and hope he continues to do well until the end of the year. Then congratulate him on his big pay day with some other team.
If Estrada does well enough, can the Jays get a comp pick assuming he leaves? If so, then let him go. If not, I wouldn't be opposed to having him back again next year at a decent price.