Have you tried the SSH connection type vs paramiko? That's just "-c ssh" in all versions and can also be configured in 0.7's configuration file.
If your SSH supports ControlPersist that should do what you want. However, if it does NOT support ControlPersist, the SSH connection type will be not as quick as paramiko. Ansible will let you know if your SSH can't support that when it tries to pass those parameters.
(If you're on older RHEL, using a Fedora machine, running playbooks from a Fedora machine isn't a bad idea.)