I don't know if there is any scientific evidence that supports the claim that hybridization makes stronger and healthier animals in both herps and mammals. I have heard of animals not being able to make it out o the eggs, not being able to reproduce, or even having birth defects. Keep in mind that mind that both indos and Aussies are the same exact species so it's not technically hybridization but a cross in locality. Equivalent to people of different race breeding.