Back in the 1960s, when "Man the Hunter" was published, researchers thought a Paleo diet was 65% plant food and 35% animal food. When Cordain did his analysis in 2000, the proportions were flipped to 35% plant food and 65% animal food. As science improves, there will likely be more refinement to the estimates of what hunter-gatherers ate.
But in the meantime, this research should be more of a guide than a bible. The idea is to find a diet that works and improves health, not create one that meets a theoretical standard. Basically, any combination of fruits, vegetables, and meats is superior to the modern crop of diets. The exact balance between these food groups is less important the overall concept. Individual experimentation is key in designing a personal diet after understanding the general Paleo framework.