Are you kidding me? It was a DDOS of 2000 static IP nodes against 4000 static IP nodes. What if a new DDOS occurs, from 8000 dynamic IP nodes?
What if a state decides to ban the whole dash network, or to DDOS it? Having static IPV4 means that you have no chance at all to survive in that case. You are 100% vulnerable to whoever central authority wishes to ban you. And I wonder, did you designed that way your network on purpose, in order NOT to survive in that case?
Why did you implemented such an awfully insecure network design, and why do you still refuse to secure your network by increasing the number of nodes?