Single target barb farming
Lohar + Richard I (level 5 of richards first skill required)
This combo is unstoppable. Kill barbarians until out of AP without returning.
Lohar + Boudica (High XP gain for both, good start combo)
Lohar + Belisarius (Fast kills, high speed)
AoE barb farming
Æthelflæd + Richard I (Fast AoE farming combo, can replace Lohar + Richard)
Sun Tzu + Richard I (AoE, tanky, but slower than Æthelflæd, costs more AP)
Richard + Yi Seong-Gye (Best combo for this is you have expertised YSG)
Note, this tree works wonders for Æthelflæd AoE farmer to.
Multi army barb farming
The goal here is to hit the barbarian with as many armies as possible as many times as possible without returning to you city.
Multi army commander options (Peacekeeper AP reduction “Insight” talent):
Æthelflæd, Lohar, Belisarius, Boudica, Markswoman
Cao Cao, Minamoto no Yoshitsune – if you don’t use them with PvP build.