All you need to do is actually just spamming cavalry, enemy never trains pikes. They will resign when all of these conditions met:

• Having less than 2 TCs.
• Having less than 3 of each type of military buildings.
• Having less than 10 military units.
• Having less than 10 villagers/trade units. With that in mind I only destroyed 4 out of 5 outposts and then rush straight to the TCs, the attack will aggro the rest of the military.