Have you found other support for this in your reading?
None so baldly stated. The classic work on early christian pagan relations is of course R. L. Fox's Pagans and Christians. However, this doesn't get us much past Constantine. There is a great series on Witchcraft and Magic called (suprise) Witchcraft and Magic in Europe and consists of 6 edited volumes. The third of these has a some papers which directly concern how the early church treated pagans, witches, etc., all of which support Hutton's statement. The Power of Sacrifice by George Heyman is good to, but it to deals mainly with persecution of christians. The only other books that come time mind as supportive (often indirectly simply because they lack any detail of christian persecution of pagans) are Early Christianity by Humphries, Second Church by MacMullen, and Religious Rivalries in the Early Roman Empire and the Rise of Christianity. Of course, my focuse has always been on Christianity and Judaism around the time of Jesus, so this is hardly my area. Hutton's specialty, though, is the history of paganism in europe.