Good young players don't bounce around the league. How many sub-30 year old QBs can you recall that suddenly became legit starting QBs on their 4th team?
Teddy is here because he's familiar with Brady's system. He's here to help the install. Unless he wildly exceeds expectations, he's a stop gap. Look at his contract. It's a stop gap contract.
Sorry some of y'all want to live in a world of homer delusion.