> this is the "cred" they built up by publishing people like me, .@OwenJones84, .@GeorgeMonbiot, .@chakrabortty -
I will challenge on the term 'occasional'.
George Monbiot writes a weekly column
Owen Jones writes a regular column
Aditya Chakrabortti writes a regular column and is their senior economics commentator.
This reduces your opening paragraph to, "By regularly publishing left wingers, by employing them on its staff, by publishing left wing material, the Guardian seeks to pass itself off as a left wing paper. " Well...yes.
I should also say that the idea that the Labour anti-semitism scandal was a plot to smear Corbyn, is not universally acknowledged even amongst left wingers.