While Huw Edward's life and career will rightly be tarnished forever, there are nuances to this case that lent him legal leniency. After initially seeking out images of legal-aged men, Williams began sending him what were clearly images of children, prompting Edwards to stop requesting more. This doesn't mean he was unaware of all the illegal images, but it does explain the reasoning behind the judge's sentencing.
There should be no nuance with respect to Huw Edwards. He paid a publicly known offender money for sexual images, so he must've known exactly what type of images he would receive. This is not a victimless crime, as is widely known. There should be no subtleties and Edwards deserves to have the very maximum the UK criminal justice system will allow.