I don't really know much about any of this but as I have only just been reading about Simon and with Paul not being around I'll quote you a little of what he says regarding Simon Magus. He quotes Rhys as saying that
"amongst the oldest instances in Welsh Poetry of the use of the word derwyddon, druids, is the one where it applied to the Magi or Wise Men....and its Irish cognate drui is not only used in the same manner, but is usually rendered into Latin by magus a magician. But now and then also, he adds, point is given to this term by making the druid into Simon Magus, whose appearance on Celtic ground is otherwise inexplicable. The Goidelic Druids accordingly appeared at times under the name of the school of Simon Druid......
These Simon Magi were soothsayers, priests and medicine men, but their principle character was perhaps that of magicians, in which guise the Simon Magus of scripture is depicted.....At any rate there is no doubt that both Britons and Romans perpetuated in various ways the memory of this great imposter and I take this to be the prima stamina of the names of our Simon Hills and seats.."
cheers