Yes. I feel certain that there is much to discover about the location of ancient sites by looking at where early churches are located. Note also any local stones like sarsens and just where they are. Excavation is not that common in churches and churchyards, but there may be other clues. In no way am I into ley lines, but there are some truly astonishing alinements of early churches. In SE Essex there are 53 churches that line up with others in 3, 4 or 5 point sequences.. Coincidence? Wishful thinking and ignoring those that don't? Relics from Roman road network? We do know that a papal edict declared that pagan temples (Saxon) should be consecrated and reused for Christian worship. So perhaps puddingstones and sarsens survive in situe from much earlier buildings. We might get some kind of answer if we make a national survey.