Enies Lobby Nami was stomping Marine Captains after her fight with Khalifa, unless you think she only Defeated Commanders
Think about that for a second and realise that Rear Admirals and Below are just gonna die from the AoE of any top tier alone(honestly a lot of The Vice Admirals too)
Shanks is the only Top Tier they would have any kind of chance against, assuming her doesn't have some kind of Fodder cleaning methods, like maybe some advanced CoC technique