ERB And SM Stirling

In his two "Lords of Creation" novels, SM Stirling follows his ERBian model to the letter.

Premise: both Mars and Venus are humanly habitable and inhabited.

Rationale (ERB did not need one): they were terraformed.

So far, so good. But Stirling goes further. The heroes of both his novels marry native princesses! This is at least possible if, as premised, the natives are not merely humanoid but fully human.

Stirling takes another step. He must combine his premise that the terraformed Mars was seeded from Earth with the tradition that Mars is an older planet. Simple:

"Although Mars was sterile until terraformed by the ancients two hundred million years ago, life on the Red Planet is, in a very real sense, 'older' than on Earth. It lacks the catastrophic mass extinction that followed the Yucatan asteroid impact of 65,000,000 mya..." (...Crimson Kings, p. 153)

Neat. I should not have to use that word but I am reduced to it.

"As a result of the uninterrupted evolutionary history, apart from a few subsequently introduced mammals, the lineages of most Martian species run back without interruption to the most successful of the late-Cretaceous introductions, birds, and the closely related therapod dinosaurs." (ibid.)

So they are older.

Poul Anderson occupies an intermediate stage: more scientifically oriented and accurate than ERB but not retro-ing like Stirling.