Lone,
I believe what E8 was saying is the Chinook can pick up some of the operational demands until the kinks are worked out on the 53-K model as Army Chinooks have supported USMC units in the sandbox before due to the Phrog's being unable to cope with the high DA's.
Swapping Hooks for 53's can work for many of the land based evolutions if the Marines will just ask for the support.