nice, I like to see co-op challenges :D I think the little ballista-man units are totally OP vs AI, with some meat shield, they'll make you win a 1v2 army clash I daresay :D
I was able to beat 1v2 titans but I couldn't do 1v3 titans. The amount of units in their armies was too much for me. Maybe with better micro I could've lured some units away while still pushing with my main army.