Towards the end of season 2 (2.15 Beefcake), a whiny Chuck felt he was not man enough to keep his girl from James Bond (Cole), the worst feeling for any man. In 3.12 American Hero, a confident Chuck not only feels man enough to leave behind the nerdy car and hop into James Bond’s (Shaw’s) cool car—clearly a symbolic act that is hugely important for Chuck’s psyche—but he actually saves James Bond and then takes the girl from him.
And Sarah goes from rolling her eyes at Chuck in 2.21 Colonel, when he wanted to get out of the car to help her save Orion, to actually volunteering Chuck to go save Kathleen in 3.10 Tic Tac.
I’d say that, from Charah’s psychological point of view, the timing is perfect. At the end of season 2, they were not equally yoked. By the end of 3.13 Other Guy, they are and they bond. (Sorry, couldn’t help the pun.)