Lol...O’Brien advised Romney in 2011 when he was the GOP standard bearer against Obama, and more recently advised Walker and then Cruz in their Presidential campaigns. None of this disqualifies him from working for Trump.
As for Coates, it wasn’t O’Brien who brought her in to the NSC or make her the head of the Middle East and North Africa policy desk. For all we know, he and Trump promoted her to draw out more hidden traitors within the National Security apparatus.
Either way, Coates was dealt with and O’Brien is busy removing a large swathe of the deep state leakers at NSC. There is absolutely no reason to remove him at this time.
Your excuses are breath-taking.
And no, Trump shouldn’t move on to his 5th NSA right now, but it is anotherv= case of bad staffing he’s stuck himself with.