I don't think that's necessary or as big a deal as you're suggesting. The savings on the later techs more than makes up for the effective double cost of the first 3 techs. For example, Animal Husbandry costs 25 or effectively 50 science. Archery costs 50 base and for everyone who gets a eureka, it costs 30, but if Babylon gets the eureka it's free for an effective savings of 30 science. Likewise horseback riding costs 120 (72 with eureka) so for Babylon it's a savings of 72 science.... On that one path alone Babylon has saved 102 science so at worst it is a minor inconvenience of not being able to make mines or reveal and pasture horses quite as quickly, but almost immediately made up for several times over.