Task/role separation when provisioning with Docker

[Gary Malouf]

I want to get an idea what the recommended way of organizing your files would be around doing the following:

1. Provision N EC2 instances of a specific size with appropriate AMI (CentOS + Docker)
2. Create container on each instance running Image A
3. Create container on each instance running Image B
4. Provision ELBs to provide HTTP access to the services

Specifically, I'm wondering what role people would put the EC2 instance creation and ELB provisioning under.  I currently have roles for deploying Image A and Image B, but the tasks for setting up the ELBs and EC2 instances respectively are just sitting in my playbook.  

My initial temptation is to create a variablized EC2 instance provisioning role, but all it's doing is putting a thin wrapper over the EC2 module.