I used Isara 1. Destroyed one Gatling with a tank, shot a mortar into the frail and finally shot a smoke grenade on the bridge. Than I ran with Audrey through and took out tanks with Audrey. I am not sure anymore how I killed the Ace. I think I try it again sometimes just to see how I did it. But in any case, I used the smoke grenade and a Lancer as main tool.
This is actually a very good strategy. I never thought of using the smoke grenade before. Somehow, I always keep forgetting it exists lol!