Correct! Although one exception i can think was Luis Scola from Spurs to Rockets. Not just same western conference but same division as well.
I'm sorry I'm not familiar with some of the players. Is Scola already a franchise player? i should follow the games more.
I was thinking along the lines of
Milwaukee to Los Angeles - Jabbar
Philadelphia to Los Angeles - Chamberlain
Minnesota to Boston - Garnett
Los Angeles to Miami - Shaq
you know, players that makes instant contenders to the receiving team that would provide additional hurdle to the original team's own championship quest. of course, there are exceptions, that's why i didn't discount the possibility just pointed out the precedent.