I am a bit suspect of the legal opinion of people like ex CJ Saeeduzzaman Siddiqui and other others because they used seniority as grounds to oust Sajjad ALi Shah on Nawaz Sharifs instigation.
On the other hand Fakhruddin Ebrahim has come out against the CJ's ruling..which is quite damning ..considering he is one of the finest legal minds in Pakistan.
Now most of the prominent lawyers are in view that the matter is different than as produced by N$ supporters. The view about Khawajah Sharif is this that CJ don't think him fit for SC. If it is so , He should be asked to go home, He should not remain there to support his leader. Only read the decision about NA 55, you can read here in thread about NA 55.