The post you are reporting:
PaulB - Comparisons are indeed valid between Coulson and Brown but there is a big difference.
Coulson is not accused of doing anything wrong while working for DC so DC has no reason to sack him.
Nothing new has been revealed, despite the hot air, that was not known about when DC employed him 2 1/2 years ago, so again no reason for DC to sack him.
Finally Coulson as editor was in the Brown position relative to McBride as the senior person responsible. Coulson, though claiming he knew nothing and was personally innocent, something no-one has been able to demonstrate is not true, decided that as the man in charge and as a point of principal he should resign. Brown, in a similar position as Coulson (but much closer to Mcbride personally than Coulson was to his journalist) used weasel words and did not resign, unlike Coulson, Brown not being a man of principal.
As for DC employing a tabloid editor, why not? Thats where many broadsheet editors and journalists learn their trade in the first place, after local press, anyway. Coulson has been very effective indeed and therefore was clearly a good choice and there has been no mud thrown at him over his role working for Cameron, let alone sticking.
It is only because of the effectiveness of the Coulson operation that Labour's spin machine, and in client newspaper, are trying to get him. Not very successfully seeing as it is a flawed case.