One of the most absurd rumors to come out of bollywood is that all khans are planning to band together against the Bachchans as part of one big khan led lobby, refusing to work with them and so on, and that is supposed to be a big problem. That is being beyond delusional. Have these people forgotten that khans themselves are facing serious charges that can keep them from working period? Apart from that, they are all entering middle age soon and will have to face that music that every artist has to go into. They are in no position to isolate the Bachchans. Salman Khan for example himself needs Amitabh Bachchan to finish his film God Tussi Great Ho where Bachchan is playing his God.
Even otherwise, making a caravan out against the Bachchans is not a good idea for a number of deeper reasons which themselves would need whole articles. But suffice to say, this is the same India and Hindi film industry where Hamid Khan had to call himself Ajith in order to get work. They don't want to return back to those days do they?
More matter of factly, and practically in terms of need, a Guru could not be stopped from smashing the box office just because Saif Ali Khan did not do the 2nd lead to Abhishek Bachchan. Dhoom 1 and Dhoom 2 were both super successful despite one featuring John Abraham alongside Abhishek Bachchan and the other featuring Hrithik Roshan alongside Abhishek Bachchan and neither featuring a single Khan.