Complex sentence: Critics of these theories argue that several alignments are likely to exist purely by chance in any such structure, and many factors such as the weathering and displacement of the stones over the millennia mean there can be no certainty of any alignments, original or otherwise.
Split into simpler sentences: Critics of these theories argue that several alignments are likely to exist purely by chance in any such structure. In addition many factors such as the weathering and displacement of the stones over the millennia mean there can be no certainty of any alignments, original or otherwise.