The amount of paganism (wiccan, islamic, or otherwise) is far less a problem than the degree of paganism parading as, residing within, the church (in Uk and USA both. ). The cAmel is already inside the tent.
Neo-Pagans are deluded but not necessarily dangerous. Their reemergence is a symptom of the dry rot in the C of E and dry rot can be fixed. Images of the Green Man in 13th century churches are a less pressing problem than the crescent spires popping up all over England.