Is there a way to divert the AI from your base when every enemy in the free for all turns their attention on you?

I was in a 12 player ffa, all AI except me. I had suffered very few raids, all of which were thwarted by a complex of walls, towers, and fortresses. I couldn't imagine anyone breaking through, except that is what the three remaining players did all of the sudden. I was able to take a few down, but since it seemed like they were taking turns hitting my walls (I was in the Jotunheim map), my villagers were in disarray. I couldn't keep up, and the most powerful of the three punched through my walls. From then, I could only watch as my army slowly depleted as my enemies flowed through the gap and destroyed my base. Now how in the Hell did my enemies suddenly turn their attention to me after practically ignoring me, and how can I prevent that from happening?