Any organisation that limits all senior appointments to internal applicants is doomed, ultimately.
That is one of the biggest reasons for the inefficiency of our civil/public service organisations.
No fresh blood, no fresh thinking - the status quo prevails - shur, it will do, this is the way we always did it.
Sure, the jobs are advertised in the media - but when has a Co Manager ever been appointed who did not come up through the ranks? Even the bank regulator was a civil servant, until recently - the change there was due to the magnificent job the previous chap did.