In my opinion it probably doesn't matter and you will have better livestock if you feed a variety of them rather then relying on giving them the best food solely. The total is greater than the total of it’s parts is it were. Just my 2 cents…anyone else?
I wonder if they eat much live vegetation in nature. I skinned a cucumber the other day for a Greek pizza I made. My G. portentosa chowed down on half of the cucumber skins and didn't leave a bit. My G. oblongonata hardly touched it though and I removed most of it, uneaten, today. Go figure!