They have invented this theory without examining the evidence or doing experiments. Lest he be dismissed as a crackpot windbag, Whitby has recently constructed his own duplicate Stonehenge, using no modern technology. Whether his methods are right or wrong, you've got to admit, it's one slick hypothesis. The construction took a mere five days. Hell, it takes me longer to make my bed.
Grease is the word.
And not just the elbow kind. Years of research led him to conclude that Stonehenge was probably constructed by maneuvering roped stones across planks greased up with some oily lubricant that was available back then, such as butter or animal fat. When you are shifting something heavy, you want to keep it going. I think the stones were dragged along a greased or iced surface such as one slippery plank on top of another, similar to a shipyard slipway. Of course, the archaeological establishment is not suffering lightly this affront from a lowly engineer.