Troop Attack Preference

I think that troops that prioritize defense structures should still defend themselves against clan castle troops. Clan castle troops are a form of defense so they are not really going outside their target priority, and it seems a little silly that they will just let those troops attack them without retaliating.
Also, troops which target anything should target the town hall at a slightly greater distance than other structures. Maybe say if the distance to the closest structure is 3 tiles and the distance to the town hall is 4 tiles it will go to the town hall but no more than that. For example, if the other closest structure was 3 tiles away and the town hall was 5, the troop would still go for the other structure.