So I love long games of Civ. Epic is my usual "pace" chosen for play. However, every time I play, regardless of my settings -- I never feel as if the world spends enough time in each given "age". A common sequence of events, is I'll discover a technology unlocking, say, a new military unit. I'll tell one of my more productive cities to begin producing them as soon as they finish their whatever-they-were-building-before, while I continue researching towards other military units, and by the time I've finished building two or so swordsman I have the tech for longswordsman and now my old troops are outdated. Later on, as my research speeds up (as it often does) I'll finally get a couple riflemen to the front lines, just in time to provide ground support for the stealth bomber I bought. Quite often I forgo the entire process and build only city-defense troops until I get into Industrial or later eras.
Is there a way to modify this? As in, set research and policy acquisition to an Epic game pace while leaving production at a slightly faster (roughly Marathon?) pace, to allow more of a chance to play around with an Ancient/Classical/Medieval military?