Just make then entry that looks like this:
Code:
                recruit "celtic infantry gaeroas" 0 requires factions { gauls, scythia, britons, } and hidden_resource NW and hidden_resource D and hidden_resource n1 and hidden_resource y2 and hidden_resource n4 and hidden_resource y8
look like this:
Code:
                recruit "celtic infantry gaeroas" 0 requires factions { gauls, scythia, britons, }