My observation with a few clutches of acanthosaura and gonocephalus, has revealed a much higher number of females per clutch, this leads me to believe they are genetically programmed to produce females.
This would avoid territoriality and assure a more reliable propagation of the specie, in theory?

Exact measurements showed males to have 1/3 longer tails then females, on this photo of siblings, both males are quit obvious, even on this low resolution pic.