Jason actually does something pretty good in this situation, for example say I'm teaming with Jason and we're playing against Cameron and Kyle. They're obviously the better team, and Jason has to have the patience and discipline to allow himself to get carried and not jump into the fight. So what he does is, if he gets a grab, he'll continue to hit them and allow them to break out (or sometimes throw them up after a lot of hits, regardless of the characters' weight). This incapacitates them for as long as possible, which allows Jason to stay alive longer, and allows me to try and kill the other guy one-on-one, whereas if Jason tried to combo them right away, they would probably get out and kill him a lot faster.
Throwing them away from me is also a good idea, since he can give up a tech chase by covering only the tech towards me and letting them to the other side of the stage. Then he can put up a wall of fairs / nairs / jabs / ftilts whatever so that they have to take the longest route possible if they want to get back to double-teaming me (which is what they want to be doing).