MNK and Earthshaker.

[Sleigh]

In Phase 1 you can just weave in and out to place the earthshakers a bit away from bahamut will still maintaining your GCD's.

Cover is better used on a BLM.

Do you have a video example? It's hard to imagine being able to place them far away enough and not running into them while doing it, while simultaneously not blocking off the side of Bahamut.

Not saying you can't do this but I just don't know exactly how it'd be done efficiently.