Its doubtful that crop yields were nearly as good in previous warm periods since we have more CO2 in the atmosphere in this one. While it does not cause much global warming as the failed hypothesis suggests, it is well established it helps plants grow much more abundantly. Moreover, it would be very dangerous to all life on this planet if it got too low.
I don't know much about comparative CO2 amounts across warm periods. Do you have info? I don't doubt you, I just like more info.
One thing I've been doing is reading through the Old Testament again, but this time paying more attention to the time period each part was about, and where it lies in warming and cooling cycles. For example, the Minoan Warm Period began about 1600 BC (some say closer to 1500 BC) and ended around 1100 BC. Moses led the people out of Egypt around 1450 BC. King Saul took the throne (beginning the Era of Kings) at perhaps 1037 BC. That means the Era of Judges occurred mainly in the Minoan Warm Period, followed by the Era of Kings mirroring the Greek Dark Age cooling period.