[I'm not too sure about the inability to create complex carvings without using metal tools. Them pre-metal fellas seemed were extremely skilled in utilising stone technologies. Just take a look at the passage grave carvings or some of the carvings on the monuments of Brittany or the Mediterranean.
Given a pretty unexhaustable supply of suitable stone and a good ]

I would go a step further and suggest that part of the social, economic , political and religious revolution of the Bronze Age resulted in RA being classed as part of the old order .