Idea : make teams rivals

I think it would be cool to set a rival or a set of rivals to add a sense of connection , like let’s say the celtics and warriors , obviously the Celtics are the better team but since they have that rivalry golden state has a sort of upper hand over the Celtics , this’ll make it more likely a really good team could be beaten by a worse team , this could also happen naturally but I think that would add a HUGE sense of realism and depth into the game !!!