classical and mythic are fine. the problem is heroic, imo. with food being scarce the 800f 500g only leads to cavalry dominance in classical. infantry aren't too food intensive per se in classical, it is that the age adv to heroic is too food intensive to allow infantry a stronger role.
if the adv to heroic was 800g and 500f then cavalry would see a more elite role instead of a constant role. there would still be raiding, but the guy defending with infantry could go heroic sooner and then boom outwards.
the scarcity and low gather rates of food in comparison to gold combined with the intense need of food to adv to heroic leads to infantry getting the screw in classical, imo.
it's not that u can't use infantry in classical, it's that u can't mass them like u can cavalry and still hit heroic at a time u could going with a raiding strat.
fh