Most churches are built to a similar design, due to tradition. We know that trading took place in Neolithic /Bronze Age Britain and Ireland, as the evidence prooves. This trading led to similar belief systems throughout Britain and Ireland, which involved stone circles, chambered tombes, barrows, not to mention mounds and standing stones. In other words, similar belief cultures evolved

This would explain sites of similar appearance throughout Britain. Just as churches are similar, but not identical, surely the same would be expected of Neolithic/Bronze Age sites.