I definitely can’t agree with that… In Tomoyo’s route he just decides to break up with Tomoyo because of the social pressure of their situation. If he really thought about the long term, then he’d realize that that wouldn’t be the right solution to her long-term issues.
Everything that Tomoya does in the early parts of CLANNAD he does because he is weak. He is insecure about his own emotions and finds an escape through the different routes. Even in Nagisa’s route he chooses to move out of his own home instead of confronting his own father.
So when you say:
He would not realize it because, again, he is very weak. His entire thought process during the route is that he does not want to end up hurting Ryou, and even if he manages to break up with Ryou, he fears that Kyou would not accept him. His entire thought process is driven by his fear to hurt other people and fear to not be accepted. And I think that fear and insecurity fits Tomoya to a T. He is not a long-term thinker, and neither is he very smart about his relationships. I personally think you give him too much credit.
Sure, he also does that. When you choose not to pursue Ryou, he tells her off. A lot of it is anchored in the choice mechanic, again. And because you do not have this choice in the Kappei route, it fails to become more believable. But analyzing his own insecurities makes me believe that he might not even have been assertive to Kyou in kappei’s route. We just don’t see that because we do not go down that timeline.