Rams are never used in Castle age, even in all-out Castle age gameplay such as, 1 player going all-out Knights and the other trying to push fast Imp with defensive Castle.
The main reason is that Rams are fairly expensive, and go down fast to Villagers juggling in and out of a Castle.
For this reason, perhaps the Ram negative melee armor could be improved from -3 to -2? A small buff to make rams viable in Castle Age. They are already countered by melee units and especially by Mangonels.